| Explanation of Responses: |
| (1) | The transaction reported involved a gift by the Reporting Person of 3,824 shares of Class A Common Stock to the McKinnon-Stachon Family Charitable Trust, a donor advised fund. |
| (2) | This transaction was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person. |
| (3) | The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $214.56 to $215.37 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or to the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| (4) | The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $215.91 to $216.00 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or to the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| (5) | The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $217.00 to $217.50 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or to the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| (6) | The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $218.24 to $218.35 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or to the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| (7) | The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $219.43 to $219.99 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or to the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| (8) | The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $220.86 to $221.85 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or to the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| (9) | The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $221.86 to $222.85 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or to the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| (10) | The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $222.86 to $223.80 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or to the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| (11) | The reported price in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $223.86 to $224.84 per share, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or to the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. |
| (12) | 25% of the shares subject to the option vested on February 1, 2019, and the remaining shares subject to the option shall vest in 36 equal monthly installments thereafter, subject to the Reporting Person's continuous employment with the Issuer on each such date. |
| (13) | 25% of the shares subject to the option vested on February 1, 2020, and the remaining shares subject to the option shall vest in 36 equal monthly installments thereafter, subject to the Reporting Person's continuous employment with the Issuer on each such date. |
| (14) | Each share of Class B Common Stock is convertible into one share of Class A Common Stock at the option of the holder and has no expiration date. |
| (15) | The shares subject to the option are fully vested and exercisable by the Reporting Person. |
| (16) | 20% of the shares subject to the option vested on July 29, 2017, 20% of the shares subject to the option vested on July 29, 2018, and the remaining shares subject to the option shall vest in 36 equal monthly installments thereafter, subject to the Reporting Person's continuous employment with the Issuer on each such date. The option is early exercisable by the Reporting Person. |
| (17) | 25% of the shares subject to the option shall vest on February 1, 2021, and the remaining shares subject to the option shall vest in 36 equal monthly installments thereafter, subject to the Reporting Person's continuous employment with the Issuer on each such date. |
| (18) | Each Restricted Stock Unit ("RSU") represents the right to receive one share of the Issuer's Class A Common Stock. |
| (19) | 25% of the shares underlying the RSU vested on March 15, 2019, and the remaining shares underlying the RSU shall vest in 12 equal quarterly installments thereafter, subject to the Reporting Person's continuous employment with the Issuer on each such date. |
| (20) | 25% of the shares underlying the RSU vested on March 15, 2020, and the remaining shares underlying the RSU shall vest in 12 equal quarterly installments thereafter, subject to the Reporting Person's continuous employment with the Issuer on each such date. |
| (21) | 25% of the shares underlying the RSU shall vest on March 15, 2021, and the remaining shares underlying the RSU shall vest in 12 equal quarterly installments thereafter, subject to the Reporting Person's continuous employment with the Issuer on each such date. |
| (22) | 17% of the shares underlying the RSU vested on June 15, 2020, 33% of the shares underlying the RSU vested on September 15, 2020, 39% of the shares underlying the RSU shall vest on December 15, 2020, and the remaining 11% of the shares underlying the RSU shall vest on March 15, 2021, subject to the Reporting Person's continuous employment with the Issuer on each such date. |