Year Percent 1950 17.26248 1955 18.20295 1960 18.59334 1965 18.87144 1970 21.06268 1975 19.30894 1980 20.90237 1985 19.29219 1990 17.74076 1995 13.98087 2000 12.69877 2005 10.71552 2010 10.01132 2015 9.36651 2020 7.66608 2025 6.74171 2030 6.45654 2035 6.3887 2040 6.20248 2045 5.86732 2050 5.55986 2055 5.39649 2060 5.33989 2065 5.33019 2070 5.30061 2075 5.25298 2080 5.18715 2085 5.14777 2090 5.12684 2095 5.11546 2100 5.10046