Northup was incorporated on January 1, 2011, and adopted a calendar year for tax purposes. It had the following gross receipts for its first six taxable years:

2011...................................................... $4,282,000
2012........................................................ 8,418,000
2013........................................................ 7,002,000
2014........................................................ 9,668,000
2015........................................................ 5,219,000
2016........................................................ 3,843,000

For which of these years is Northup exempt from AMT?