Year Percent 1950 29.02586 1955 28.14526 1960 27.32568 1965 26.38352 1970 25.27651 1975 25.26449 1980 27.29573 1985 27.91457 1990 27.63305 1995 24.12675 2000 22.89893 2005 25.67578 2010 27.63774 2015 28.56399 2020 28.36256 2025 27.96469 2030 28.39333 2035 29.32849 2040 30.58058 2045 31.40136 2050 31.38858 2055 31.11592 2060 30.97082 2065 31.05923 2070 31.20402 2075 31.15396 2080 30.85009 2085 30.46383 2090 30.16604 2095 29.97036 2100 29.77793