Year Percent 1950 13.41943 1955 16.24262 1960 18.00815 1965 19.21434 1970 20.96031 1975 21.15374 1980 20.38111 1985 19.60413 1990 21.10661 1995 24.31924 2000 28.43837 2005 33.44965 2010 33.56947 2015 32.41679 2020 29.18505 2025 26.68418 2030 25.67731 2035 25.52054 2040 25.03813 2045 23.34159 2050 22.43662 2055 21.60554 2060 22.26862 2065 24.19932 2070 25.29149 2075 25.4574 2080 24.40404 2085 23.1019 2090 22.17522 2095 22.18626 2100 22.71053