Year Percent 1950 8.02802 1955 8.55475 1960 9.04251 1965 10.04979 1970 11.31213 1975 12.12246 1980 12.5464 1985 13.5636 1990 16.78427 1995 18.12504 2000 19.27479 2005 19.91332 2010 22.24374 2015 24.55458 2020 26.7679 2025 29.27239 2030 31.63143 2035 34.47137 2040 36.74501 2045 37.90963 2050 38.17606 2055 38.29458 2060 38.70395 2065 39.3028 2070 39.76387 2075 39.99202 2080 39.88016 2085 39.66962 2090 39.6017 2095 39.64287 2100 39.74053