Year	Percent
1950	11.72625
1955	13.13219
1960	13.86468
1965	14.76376
1970	15.42485
1975	13.07718
1980	12.47502
1985	10.60132
1990	11.13391
1995	9.76374
2000	9.90307
2005	8.07398
2010	6.56795
2015	6.71329
2020	6.56681
2025	6.29475
2030	5.99562
2035	5.64572
2040	5.30065
2045	5.08546
2050	5.05418
2055	5.07811
2060	5.03912
2065	4.94809
2070	4.84796
2075	4.78287
2080	4.77262
2085	4.79969
2090	4.81984
2095	4.80045
2100	4.75379