Year Percent 1950 14.12912 1955 14.00104 1960 15.06609 1965 15.22008 1970 15.33301 1975 14.99011 1980 14.95368 1985 14.89645 1990 13.80539 1995 13.17707 2000 13.41648 2005 12.94983 2010 11.0872 2015 10.16 2020 9.58102 2025 9.29861 2030 8.74545 2035 8.06696 2040 7.392 2045 6.83051 2050 6.43223 2055 6.14464 2060 5.87118 2065 5.58417 2070 5.3027 2075 5.08353 2080 4.93658 2085 4.85412 2090 4.79646 2095 4.74215 2100 4.67734