Year Percent 1950 7.69586 1955 10.08472 1960 11.15539 1965 10.77601 1970 8.15248 1975 7.10021 1980 7.53974 1985 8.29992 1990 8.44721 1995 7.24359 2000 6.27772 2005 5.02376 2010 4.40968 2015 4.92793 2020 4.70937 2025 4.31036 2030 3.95008 2035 3.73244 2040 3.63805 2045 3.74101 2050 3.88525 2055 3.9054 2060 3.81775 2065 3.75288 2070 3.77422 2075 3.9022 2080 4.07635 2085 4.19974 2090 4.23292 2095 4.20507 2100 4.19351