Year Percent 1950 17.86304 1955 18.45903 1960 16.85779 1965 14.19837 1970 12.50527 1975 12.63476 1980 12.30948 1985 11.16168 1990 9.868 1995 9.82867 2000 10.15976 2005 12.78724 2010 15.88267 2015 16.92434 2020 18.08802 2025 19.72405 2030 22.40061 2035 25.30944 2040 27.41126 2045 28.06405 2050 27.75705 2055 27.09262 2060 26.69802 2065 26.55651 2070 26.3666 2075 26.08709 2080 25.54399 2085 24.94805 2090 24.4587 2095 24.09998 2100 23.81996