Year Percent 1950 9.90764 1955 9.85312 1960 9.16881 1965 10.36135 1970 11.93643 1975 11.17531 1980 10.00346 1985 9.85734 1990 12.40602 1995 13.56348 2000 14.91127 2005 16.3775 2010 17.11538 2015 18.99916 2020 20.92307 2025 22.96585 2030 24.19639 2035 25.2211 2040 25.67749 2045 26.19542 2050 27.36619 2055 29.06452 2060 29.49812 2065 28.96534 2070 28.74203 2075 29.18414 2080 29.73693 2085 30.4529 2090 30.96618 2095 31.13236 2100 31.22047