Year	Percent
1950	12.82128
1955	13.40397
1960	12.99831
1965	13.91299
1970	14.38995
1975	14.79432
1980	14.11671
1985	13.36084
1990	12.54825
1995	11.73304
2000	10.6749
2005	10.01618
2010	9.46531
2015	8.44731
2020	8.13493
2025	7.46576
2030	7.00676
2035	6.53098
2040	6.13952
2045	5.86026
2050	5.67885
2055	5.52499
2060	5.36574
2065	5.2101
2070	5.06003
2075	4.9572
2080	4.89202
2085	4.84899
2090	4.79435
2095	4.73497
2100	4.68164