Year Percent 1950 3.41946 1955 3.83916 1960 4.52416 1965 5.01016 1970 6.57608 1975 8.35269 1980 9.21186 1985 10.17978 1990 12.89323 1995 14.23918 2000 14.89546 2005 15.57925 2010 18.43649 2015 21.79922 2020 25.99227 2025 30.22138 2030 32.90187 2035 35.278 2040 37.45517 2045 39.5155 2050 40.62545 2055 41.13121 2060 40.40306 2065 38.67797 2070 37.65952 2075 36.94894 2080 37.02302 2085 37.39835 2090 37.86405 2095 37.95191 2100 37.94706