Year Percent 1950 26.16597 1955 26.43552 1960 26.64943 1965 25.62062 1970 24.36351 1975 22.51158 1980 22.88182 1985 22.65021 1990 23.74614 1995 24.93551 2000 26.76273 2005 28.46585 2010 30.0031 2015 29.96657 2020 29.36772 2025 28.1324 2030 26.62723 2035 25.62287 2040 24.78992 2045 24.47711 2050 24.40813 2055 23.99436 2060 23.88794 2065 23.63719 2070 23.55033 2075 23.49527 2080 23.43049 2085 23.30231 2090 23.12373 2095 22.92363 2100 22.73126