Year Percent 1950 10.20652 1955 9.22177 1960 8.91244 1965 8.92175 1970 10.74035 1975 11.07873 1980 10.7569 1985 10.913 1990 14.30038 1995 16.65994 2000 18.46971 2005 19.01004 2010 20.00461 2015 22.44839 2020 24.63051 2025 26.77593 2030 28.09278 2035 29.80112 2040 31.45511 2045 33.27031 2050 34.46425 2055 35.70703 2060 36.75794 2065 37.43199 2070 38.17501 2075 38.67022 2080 38.96233 2085 39.17228 2090 39.35192 2095 39.52666 2100 39.75016