ABC Inc. sells a monthly magazine called "The K". ABC Inc.has chosen a December 31 fiscal year end and began operations in 2020.During the year ended December 31, 2020 ABC Inc. received customer subscription payments as follows:

Subscriptions for the period October 2020-September 2021 $ 3600

Subscriptions for the period November 2020-October 2021 $ 7140

Subscriptions for the period December 2020-November 2021 $ 6540

ABC Inc. delivered the magazine subscriptions for October, November and December. Calculate the amount of subscriptions revenue ABC Inc. will recognize for the year ended December 31, 2020.