Year Percent 1950 28.37359 1955 28.56312 1960 25.48778 1965 24.03253 1970 22.56609 1975 21.72344 1980 23.69014 1985 24.61042 1990 25.25053 1995 24.54821 2000 26.37011 2005 27.87395 2010 29.90208 2015 30.15778 2020 29.07766 2025 27.70243 2030 26.40141 2035 26.34668 2040 26.03282 2045 24.79778 2050 23.50989 2055 22.45172 2060 22.52273 2065 22.97732 2070 23.35523 2075 23.35629 2080 22.96155 2085 22.51423 2090 22.27651 2095 22.30246 2100 22.40786