Year Percent 1950 6.58647 1955 13.47567 1960 13.82142 1965 13.79547 1970 13.27447 1975 9.56177 1980 8.16778 1985 7.91448 1990 7.23381 1995 6.4014 2000 6.36784 2005 5.23835 2010 3.99625 2015 4.26397 2020 4.5754 2025 5.41078 2030 5.59819 2035 5.46913 2040 4.79604 2045 4.42805 2050 4.53846 2055 4.92542 2060 5.29252 2065 5.43854 2070 5.29772 2075 5.01699 2080 4.84427 2085 4.87496 2090 5.01941 2095 5.12411 2100 5.10459