Year Percent 1950 9.69717 1955 7.02975 1960 5.71038 1965 5.3669 1970 5.53898 1975 5.99834 1980 6.49159 1985 7.01912 1990 8.19268 1995 8.65994 2000 8.90213 2005 9.72287 2010 10.76859 2015 12.81286 2020 15.11971 2025 17.44554 2030 19.67312 2035 21.61526 2040 23.81423 2045 25.32846 2050 26.12572 2055 27.03644 2060 28.1178 2065 29.74202 2070 31.72307 2075 33.29211 2080 34.54223 2085 35.4314 2090 36.1463 2095 36.8939 2100 37.63834