What is this answer?

Question

The number of visits to public libraries increased from 1.3

billion in 1996 to 1.6 billion in 2001. Find the average rate of change in the number of public library visits from 1996 to 2001.

The average rate of change between 1996 and 2001 was how many billion visits per year?

Answer 1

Average rate of change = Change in visits ÷ Change in time = Δv/Δt

r = (1.6-1.3)/(2001-1996) = .3/5 = 0.06 billion visits per year = 60 million visits per year