Year	Percent
1950	18.49476
1955	18.31833
1960	18.79016
1965	19.34485
1970	17.4785
1975	15.42155
1980	15.04687
1985	14.51349
1990	14.09773
1995	12.82065
2000	11.73604
2005	10.99967
2010	10.40128
2015	9.80322
2020	9.15531
2025	8.53509
2030	7.99701
2035	7.51633
2040	7.10508
2045	6.75109
2050	6.42317
2055	6.13927
2060	5.89022
2065	5.67978
2070	5.5021
2075	5.35206
2080	5.2251
2085	5.1204
2090	5.02949
2095	4.96077
2100	4.90861