Year Percent 1950 13.58419 1955 11.79836 1960 10.66207 1965 11.26349 1970 12.58163 1975 15.60691 1980 10.9692 1985 12.49472 1990 13.20182 1995 12.58596 2000 11.91208 2005 10.47461 2010 9.76463 2015 9.29447 2020 9.3955 2025 8.6877 2030 8.12792 2035 7.58442 2040 7.12932 2045 6.79385 2050 6.56883 2055 6.37512 2060 6.18523 2065 5.98422 2070 5.81472 2075 5.68305 2080 5.58252 2085 5.50587 2090 5.42793 2095 5.35056 2100 5.27306