Year	Percent
1950	8.21974
1955	7.74222
1960	8.77184
1965	8.5613
1970	7.51585
1975	7.49787
1980	7.01451
1985	6.93676
1990	7.13483
1995	6.68815
2000	5.89882
2005	4.81744
2010	4.36485
2015	4.24101
2020	4.86946
2025	5.10167
2030	4.91398
2035	4.5844
2040	4.29728
2045	4.25618
2050	4.48668
2055	4.77983
2060	4.90313
2065	4.826
2070	4.68675
2075	4.63721
2080	4.72295
2085	4.86152
2090	4.94003
2095	4.89141
2100	4.7692
