Year Percent 1950 5.58543 1955 5.22393 1960 4.91997 1965 4.85471 1970 4.87484 1975 5.45509 1980 5.97096 1985 6.81709 1990 8.19972 1995 8.89627 2000 9.45528 2005 10.26329 2010 12.19515 2015 15.32009 2020 18.34427 2025 21.68774 2030 24.91342 2035 27.02802 2040 28.50727 2045 29.08079 2050 29.35847 2055 29.86261 2060 30.92623 2065 32.50021 2070 33.877 2075 35.30448 2080 36.47511 2085 37.53484 2090 38.53134 2095 39.41118 2100 40.103