The number of U. S. citizens aged 65 years and older from 1900 through 2050 is estimated to be growing at the rate of

R(t) = 0.063t2 − 0.48t + 3.87 (0 ≤ t ≤ 15)

million people/decade, where t is measured in decades, with t = 0 corresponding to 1900.† How many times faster will the average rate of growth of U. S. citizens aged 65 yr and older between 2000 and 2050 be than that between 1900 and 1950. (Round your answer to two decimal places.)