Year	Percent
1950	13.34586
1955	13.61616
1960	14.17007
1965	15.00887
1970	15.53973
1975	14.45713
1980	13.63389
1985	13.13433
1990	12.62293
1995	11.73524
2000	9.80342
2005	8.22777
2010	7.45226
2015	7.59768
2020	8.58049
2025	8.0033
2030	7.16821
2035	6.36439
2040	5.89533
2045	5.85671
2050	5.98529
2055	5.9747
2060	5.7377
2065	5.40429
2070	5.17715
2075	5.12733
2080	5.17841
2085	5.20533
2090	5.1377
2095	4.99876
2100	4.87726