The first table displays Congressional Budget Office forecasts made in January 2015 of future federal budget deficits. Compare these forecasts with actual deficits for those same years (see the second table), and then answer the questions.

Year:	2015	2016	2017	2018	2019	2020
Deficit forecast (in billions of dollars)	468	467	489	540	652	739

Fiscal Year	Budget Balance =	Cyclical Component +	Structural Component
2015	439	86	353
2016	585	76	509
2017	665	53	612
2018	779	11	790
2019	984	53	1,037
2020	1,074	87	1,161

a. From 2015-2020, in how many years was the CBO too optimistic (underestimating the deficit)?

b. During this same period, in how many years was the CBO too pessimistic?

c. In which year the the CBO miss their estimate by the largest amount?

d. How much was added to the national debt from 2015 through 2020? $ trillion

e. During the same years, how much was the national debt increased from the cyclical component? $ billion