Year Percent 1950 4.50999 1955 4.41521 1960 3.8671 1965 3.62277 1970 3.46394 1975 3.6967 1980 3.97502 1985 4.14719 1990 4.66836 1995 5.78052 2000 7.48165 2005 9.16971 2010 10.12426 2015 9.84463 2020 12.14177 2025 13.61367 2030 16.96412 2035 19.85585 2040 20.31544 2045 21.36688 2050 22.44355 2055 23.89949 2060 25.27168 2065 26.50757 2070 27.33562 2075 28.15235 2080 29.14225 2085 30.22755 2090 31.23211 2095 32.01567 2100 32.57997