Calculate real growth per capita in the following countries:
a. Democratic Republic of Congo: population growth = 3.0 percent; real output growth = 1.8 percent.
b. Estonia: population growth = -0.4 percent; real output growth = 4.2 percent.
c. India: population growth = 2.0 percent; real output growth = 6 percent.
d. United States: population growth = 0.5 percent; real output growth = 2.5 percent.