Year	Percent
1950	13.4022
1955	14.83509
1960	15.36551
1965	15.0789
1970	11.84174
1975	9.53547
1980	9.31315
1985	8.75632
1990	8.30933
1995	7.81762
2000	7.33615
2005	7.02561
2010	6.68819
2015	6.45356
2020	6.24814
2025	6.08876
2030	5.9668
2035	5.89388
2040	5.8629
2045	5.84388
2050	5.81162
2055	5.76965
2060	5.71147
2065	5.65885
2070	5.60356
2075	5.55231
2080	5.49512
2085	5.43141
2090	5.37602
2095	5.32578
2100	5.28403