Year Percent 1950 10.16203 1955 12.19661 1960 12.36076 1965 11.6213 1970 11.62402 1975 10.07107 1980 9.30098 1985 8.26778 1990 7.87014 1995 7.29609 2000 6.51287 2005 5.91994 2010 4.54465 2015 4.64765 2020 4.41322 2025 4.45662 2030 4.57754 2035 4.50248 2040 4.26195 2045 4.08083 2050 4.06748 2055 4.17858 2060 4.32312 2065 4.39587 2070 4.36065 2075 4.29864 2080 4.3014 2085 4.38748 2090 4.50303 2095 4.57232 2100 4.56408