Year	Percent
1950	6.42191
1955	6.6452
1960	6.81647
1965	7.38345
1970	8.03269
1975	7.25968
1980	6.23812
1985	5.42382
1990	5.48977
1995	6.11636
2000	6.07401
2005	5.55673
2010	5.02854
2015	5.11781
2020	4.92359
2025	4.78902
2030	4.72112
2035	4.68294
2040	4.64629
2045	4.61361
2050	4.59583
2055	4.60211
2060	4.62265
2065	4.64932
2070	4.66601
2075	4.66406
2080	4.65216
2085	4.64165
2090	4.62644
2095	4.61172
2100	4.59023
