Year Percent 1950 12.59693 1955 12.43201 1960 12.40245 1965 12.46766 1970 13.23482 1975 14.636 1980 15.12529 1985 16.06173 1990 18.08455 1995 19.83435 2000 22.42721 2005 25.91565 2010 27.30796 2015 27.46305 2020 28.06476 2025 26.94992 2030 26.72888 2035 28.07209 2040 27.87788 2045 28.89865 2050 28.86858 2055 26.88357 2060 25.30116 2065 23.67002 2070 23.19505 2075 23.5481 2080 23.80794 2085 23.65742 2090 23.17743 2095 22.75683 2100 22.6384