Year Percent 1950 8.08481 1955 7.30981 1960 6.86459 1965 7.92307 1970 8.59725 1975 8.17416 1980 6.66978 1985 5.65189 1990 5.77697 1995 5.82408 2000 5.88428 2005 5.22929 2010 4.83952 2015 4.63239 2020 4.68283 2025 4.8623 2030 4.85794 2035 4.69209 2040 4.48066 2045 4.37708 2050 4.42865 2055 4.57407 2060 4.70902 2065 4.74115 2070 4.68894 2075 4.62553 2080 4.62388 2085 4.67566 2090 4.73642 2095 4.75269 2100 4.71179