Year Percent 1950 13.93859 1955 13.3036 1960 13.64565 1965 15.42508 1970 14.19083 1975 12.58722 1980 11.74425 1985 9.71286 1990 8.92286 1995 6.86702 2000 7.36053 2005 6.5133 2010 5.07847 2015 4.52076 2020 4.34214 2025 4.35398 2030 4.36293 2035 4.40289 2040 4.23601 2045 3.90974 2050 3.77865 2055 3.87377 2060 4.07135 2065 4.26932 2070 4.38408 2075 4.3543 2080 4.24176 2085 4.20977 2090 4.29763 2095 4.43792 2100 4.54151