Year Percent 1950 12.4238 1955 12.89928 1960 13.24105 1965 13.76374 1970 14.33 1975 14.82486 1980 15.36963 1985 15.95553 1990 17.25054 1995 18.85182 2000 22.02365 2005 23.64006 2010 24.16533 2015 24.64731 2020 25.54349 2025 26.13093 2030 26.08142 2035 25.78557 2040 24.65569 2045 24.28265 2050 24.81767 2055 25.08688 2060 25.13101 2065 24.30797 2070 23.11426 2075 22.56573 2080 22.48769 2085 22.58838 2090 22.51057 2095 22.08253 2100 21.4881