Year	Percent
1950	12.15933
1955	11.84605
1960	12.18649
1965	11.47277
1970	10.53585
1975	9.81077
1980	8.15377
1985	7.70244
1990	8.13443
1995	8.05685
2000	7.34481
2005	6.88149
2010	7.14528
2015	6.6893
2020	6.4701
2025	6.25941
2030	6.01024
2035	5.75988
2040	5.5965
2045	5.50752
2050	5.42826
2055	5.34928
2060	5.25446
2065	5.15486
2070	5.06615
2075	4.99641
2080	4.93832
2085	4.89186
2090	4.84359
2095	4.79297
2100	4.74187