Year Percent 1950 3.60305 1955 3.33199 1960 3.50128 1965 3.45406 1970 3.59627 1975 3.97722 1980 4.27303 1985 4.81719 1990 5.89503 1995 6.39057 2000 6.55633 2005 6.94052 2010 7.2055 2015 8.01511 2020 9.27707 2025 10.73159 2030 12.31948 2035 13.41713 2040 14.0393 2045 14.27988 2050 14.35874 2055 15.3166 2060 16.70641 2065 18.34491 2070 20.85445 2075 22.88904 2080 24.36201 2085 25.69239 2090 27.1136 2095 28.78879 2100 30.54387