The table below provides a summary of reserves associated with the Kaiser indemnity obligations from December 31, 2016, through December 31, 2019: We have various long-term supply contracts and distribution agreements with unaffiliated third parties and our joint venture partners to purchase materials used in production and packaging and to provide distribution services. The supply contracts provide that we purchase certain minimum levels of materials throughout the terms of the contracts. Additionally, we have various long-term non-cancelable commitments for advertising, sponsorships and promotions, including marketing at sports arenas, stadiums and other venues and events. The future aggregate minimum required commitments under these purchase obligations are shown in the table below based on foreign exchange rates as of December 31, 2019. The amounts in the table do not represent all anticipated payments under long-term contracts. Rather, they represent unconditional, non-cancelable purchase commitments under contracts with remaining terms greater than one year. Total purchases under our supply and distribution contracts in 2019, 2018 and 2017 were approximately $1.0 billion, $1.1 billion and $1.2 billion, respectively. Total marketing and advertising expense was approximately $1.2 billion, $1.2 billion and $1.3 billion in 2019, 2018 and 2017, respectively. Related to litigation, other disputes and environmental issues, we have an aggregate accrued contingent liability of $16.2 million and $13.7 million as of December 31, 2019 and December 31, 2018, respectively. While we cannot predict the eventual aggregate cost for litigation, other disputes and environmental matters in which we are currently involved, we believe adequate reserves have been provided for losses that are probable and estimable. Additionally, as noted below, there are certain loss contingencies that we deem reasonably possible for which a range of loss is not estimable at this time; for all other matters, we believe that any reasonably possible losses in excess of the amounts accrued are immaterial to our consolidated financial statements. We are involved in other disputes and legal actions arising in the ordinary course of our business. While it is not feasible to predict or determine the outcome of these proceedings, in our opinion, based on a review with legal counsel, other than as 138 Litigation and Other Disputes and Environmental Purchase Obligations Year Supply and Distribution Advertising and Promotions (Amounts in millions) 2020 $ 467.6 $ 100.2 2021 372.2 97.9 2022 341.3 77.6 2023 225.4 63.8 2024 118.6 60.8 Thereafter 458.4 155.0 Total $ 1,983.5 $ 555.3 Total indemnity reserves (In millions) Balance as of December 31, 2016 $ 17.6 Changes in estimates — Foreign exchange impacts (0.3 ) Balance as of December 31, 2017 $ 17.3 Changes in estimates — Foreign exchange impacts (2.6) Balance as of December 31, 2018 $ 14.7 Changes in estimates — Foreign exchange impacts (0.5 ) Balance as of December 31, 2019 $ 14.2