Year Percent 1950 5.68913 1955 4.73936 1960 4.46627 1965 4.39218 1970 4.46434 1975 4.56015 1980 4.60297 1985 4.72243 1990 5.29946 1995 5.4562 2000 5.57917 2005 5.72966 2010 6.03642 2015 6.62796 2020 7.2329 2025 7.86465 2030 8.55236 2035 9.35627 2040 10.26897 2045 11.20066 2050 12.03112 2055 12.93678 2060 14.09091 2065 15.28859 2070 16.48565 2075 17.59541 2080 18.68493 2085 19.78281 2090 20.88295 2095 21.98849 2100 23.08664