Year	Percent
1950	18.0542
1955	19.65599
1960	19.62426
1965	19.45933
1970	19.63351
1975	19.27576
1980	19.19591
1985	18.60393
1990	17.72834
1995	17.01371
2000	15.76603
2005	14.30263
2010	12.48507
2015	10.89774
2020	10.18267
2025	9.48526
2030	8.75368
2035	8.01741
2040	7.37144
2045	6.84741
2050	6.42427
2055	6.09336
2060	5.80995
2065	5.573
2070	5.34682
2075	5.17104
2080	5.03529
2085	4.94029
2090	4.86759
2095	4.80871
2100	4.75093