Year	Percent
1950	8.176
1955	8.51152
1960	8.37494
1965	9.01884
1970	9.1218
1975	8.6545
1980	8.37868
1985	7.83163
1990	6.17772
1995	5.06035
2000	4.58923
2005	4.33974
2010	4.71079
2015	5.04433
2020	4.46314
2025	4.10082
2030	3.80111
2035	3.69088
2040	3.76829
2045	3.9327
2050	4.04434
2055	4.01711
2060	3.93581
2065	3.91073
2070	3.97544
2075	4.10287
2080	4.22298
2085	4.26473
2090	4.22725
2095	4.15593
2100	4.11492