Year Percent 1950 11.28821 1955 10.84208 1960 10.36091 1965 10.91391 1970 11.67055 1975 12.52834 1980 11.88162 1985 12.48518 1990 16.59544 1995 17.73518 2000 19.21999 2005 18.56053 2010 19.0755 2015 20.40342 2020 22.70883 2025 24.71249 2030 25.73018 2035 26.83534 2040 27.98309 2045 29.64942 2050 31.43753 2055 31.79859 2060 30.83606 2065 29.86739 2070 29.74412 2075 30.41482 2080 31.01134 2085 31.41888 2090 31.55752 2095 31.64572 2100 31.96148