Year Percent 1950 27.58809 1955 27.74549 1960 27.81962 1965 27.89518 1970 27.11103 1975 24.71107 1980 24.13793 1985 23.92822 1990 23.81793 1995 22.9462 2000 24.24094 2005 26.55466 2010 29.66276 2015 32.38971 2020 33.20011 2025 33.38068 2030 33.23107 2035 33.03502 2040 33.25307 2045 33.30592 2050 32.9569 2055 32.24166 2060 31.49039 2065 30.79904 2070 30.12399 2075 29.35479 2080 28.48078 2085 27.55984 2090 26.65988 2095 25.88532 2100 25.2709