Year Percent 1950 21.2739 1955 21.58061 1960 21.30402 1965 21.21628 1970 20.90243 1975 20.96466 1980 21.6891 1985 22.6349 1990 25.1214 1995 26.72655 2000 28.35187 2005 29.7756 2010 29.73833 2015 29.05181 2020 27.41088 2025 25.51295 2030 24.22083 2035 23.9905 2040 24.44798 2045 24.92396 2050 24.6558 2055 24.04504 2060 23.69405 2065 23.32504 2070 23.32935 2075 23.46888 2080 23.3862 2085 23.09009 2090 22.7579 2095 22.54665 2100 22.48891