Year	Percent
1950	16.22235
1955	17.59284
1960	18.0529
1965	18.00913
1970	17.37566
1975	16.76795
1980	16.08429
1985	14.71304
1990	13.60304
1995	13.14038
2000	12.05668
2005	10.09177
2010	9.10043
2015	8.47708
2020	8.14186
2025	7.58776
2030	6.9443
2035	6.33488
2040	5.83775
2045	5.49124
2050	5.24643
2055	5.01895
2060	4.78242
2065	4.55178
2070	4.37245
2075	4.25091
2080	4.18176
2085	4.13714
2090	4.10243
2095	4.0634
2100	4.03019
