Using production and geological data, the management of an oil company estimates that oil will be pumped from a field producing at a rate given by

S'(t) = 20 - 20e^-0.05t              0<=t<=24

where R(t) is the rate of production (in thousands of barrels per year) t years after pumping begins. How many barrels of oil Q(t) will the field produce in the first t years if Q(0) = 0? How many barrels will be produced in the first 9 years?