Year Percent 1950 4.94644 1955 4.8674 1960 5.82108 1965 4.61425 1970 6.12589 1975 7.05088 1980 8.16636 1985 8.50322 1990 10.04318 1995 11.24009 2000 12.59498 2005 14.01934 2010 18.07298 2015 20.8788 2020 24.18328 2025 27.96035 2030 30.11451 2035 31.3428 2040 30.37585 2045 28.52709 2050 27.00027 2055 27.86369 2060 29.88989 2065 31.85348 2070 33.41357 2075 34.76678 2080 35.48452 2085 36.15642 2090 36.9845 2095 37.72271 2100 38.17292