23 Table of Contents Reference Number per Item 601 of Regulation S- K Description of Exhibits Exhibit Number in this Form 10-K The instrument defining the rights of the holders of the 7.125% Debentures due 2096 is Exhibit 4.2 to Form 8-K/A, filed on December 6, 1996, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 6.22% Debentures due 2027 is Exhibit 3 to Form 8-K, filed on August 1, 1997, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 6.50% Debentures due 2028 is Exhibit 2 to Form 8-K, filed on January 8, 1998, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 2.900% Notes due 2021 is Exhibit 3.1 to Form 8-K, filed October 31, 2011, and is hereby incorporated by reference. The instruments defining the rights of the holders of the 1.875% Notes due 2022 is Exhibit 2.1 to Form 8-K, filed July 27, 2012, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 1.625% Notes due 2020 is Exhibit 3.1 to Form 8-K, filed May 6, 2013, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 3.375% Notes due 2023 is Exhibit 2 to Form 8-K, filed July 31, 2013, and is hereby incorporated by reference. The instruments defining the rights of the holders of the 1.875% Notes due 2020 and 2.875% Notes due 2025 are Exhibits 2 and 3 to Form 8-K, filed November 6, 2013, and are hereby incorporated by reference. The instrument defining the rights of the holders of the 2.750% Notes due 2020 is Exhibit 2 to Form 8-K, filed November 20, 2013, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 3.625% Notes due 2024 is Exhibit 5 to Form 8-K, filed February 11, 2014, and is hereby incorporated by reference. The instrument defining the rights of the holders of the Floating Rate Notes due 2021 is Exhibit 2 to Form 8-K, filed November 5, 2014, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 1.250% Notes due 2023 is Exhibit 2 to Form 8-K, filed November 25, 2014, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 2.625% Notes due 2022 is Exhibit 2 to Form 8-K, filed on August 4, 2015, and is hereby incorporated by reference. The instrument defining the rights of the holders of the 2.875% Notes due 2022 is Exhibit 2 to Form 8-K, filed on November 6, 2015, and is hereby incorporated by reference. The instruments defining the rights of the holders of the 2.250% Notes due 2021, 3.450% Notes due 2026 and 4.700% Notes due 2046 are Exhibits 4.3, 4.4 and 4.5 to Form 8-K filed February 18, 2016, and are hereby incorporated by reference. The instruments defining the rights of the holders of the 0.500% Notes due 2021, 1.125% Notes due 2024 and 1.750% Notes due 2028 are Exhibits 4.1, 4.2 and 4.3 to Form 8-K filed March 4, 2016, and are hereby incorporated by reference.