Baker Company is trying to determine how often it needs to deposit payroll taxes for calendar year 2018. The company made the following quarterly payroll tax deposits during the last two years:

Quarter beginning January 1, 2016…………….…….     $ 10,000

Quarter beginning April 1,  2016………….…….. .             10,000

Quarter beginning July 1, 2016…………….………..            11,000

Quarter beginning October 1,2016. . .…..…………          12,000

Quarter beginning January 1, 2017. . .……….............     12,000

Quarter beginning April 1, 2017. . . . . . . . . ….………      12,000

Quarter beginning July 1, 2017. . . . ………….…….           11,000

Quarter beginning October 1, 2017. . . …..…………..      12,000

a. What is the amount from the lookback period?

b. In 2018 how often must Baker Company make payroll deposits?