Aduro Clean Technologies has the following share outstanding since their initial share offering: 31,000 shares of $3 cumulative preferred shares 60,000 common shares issued at $10 each The board of directors has declared the following dividends: 2017 none 2018 $50,000 2019 $80,000 2020 $150,000 2021 $260,000 At the end of 2020, how much was the total cumulative dividend arrears available for preferred shareholders?