Year Percent 1950 13.88683 1955 14.12164 1960 14.29297 1965 14.50016 1970 14.46741 1975 14.22253 1980 13.97877 1985 13.64873 1990 13.05607 1995 12.89623 2000 12.8093 2005 12.7416 2010 13.1028 2015 13.60266 2020 14.24375 2025 14.98088 2030 15.57224 2035 16.00775 2040 16.75626 2045 17.74938 2050 18.80622 2055 19.79945 2060 20.53788 2065 21.09094 2070 21.63766 2075 22.21683 2080 22.74176 2085 23.16855 2090 23.4995 2095 23.76756 2100 23.98278