Year Percent 1950 12.32436 1955 13.70638 1960 13.58749 1965 14.22027 1970 13.34346 1975 12.79113 1980 11.66099 1985 11.58458 1990 11.0918 1995 9.65827 2000 8.79562 2005 8.28083 2010 8.54462 2015 8.44285 2020 7.62379 2025 7.00534 2030 6.48294 2035 6.19962 2040 6.11963 2045 6.0209 2050 5.75687 2055 5.42352 2060 5.15557 2065 5.023 2070 4.99254 2075 4.98953 2080 4.90746 2085 4.76085 2090 4.62076 2095 4.55728 2100 4.57244