Year Percent 1950 17.31167 1955 17.82616 1960 18.62111 1965 13.53275 1970 12.53044 1975 8.75041 1980 9.39906 1985 10.7849 1990 9.74451 1995 7.36853 2000 6.44342 2005 4.76091 2010 3.56712 2015 3.58916 2020 3.2011 2025 3.01771 2030 3.07495 2035 3.20707 2040 3.26689 2045 3.22664 2050 3.1771 2055 3.19108 2060 3.25376 2065 3.33182 2070 3.38592 2075 3.42152 2080 3.4458 2085 3.49505 2090 3.56519 2095 3.64443 2100 3.71675