Year Percent 1950 26.90983 1955 25.16879 1960 22.28703 1965 22.10169 1970 24.15162 1975 26.84186 1980 28.45425 1985 29.54908 1990 28.56551 1995 29.50885 2000 31.45832 2005 33.18906 2010 32.29548 2015 27.41978 2020 24.44057 2025 23.46297 2030 24.63894 2035 26.20195 2040 26.65166 2045 25.73671 2050 24.10644 2055 22.95989 2060 22.80061 2065 23.30984 2070 23.7722 2075 23.66982 2080 23.0247 2085 22.2645 2090 21.8 2095 21.74339 2100 21.88914