Year Percent 1950 6.621 1955 6.93077 1960 7.11328 1965 7.46707 1970 7.40101 1975 6.94834 1980 7.02367 1985 7.06595 1990 8.15969 1995 8.48699 2000 8.63967 2005 8.63435 2010 8.87626 2015 10.28176 2020 12.52068 2025 14.99781 2030 17.5188 2035 20.17307 2040 22.77907 2045 25.49586 2050 28.2898 2055 30.76778 2060 31.51915 2065 31.82981 2070 32.47833 2075 33.39529 2080 34.16626 2085 34.84985 2090 35.16689 2095 35.26599 2100 35.48101