Year	Percent
1950	5.79271
1955	6.0109
1960	6.16022
1965	6.67174
1970	7.25055
1975	6.64604
1980	5.51741
1985	5.0602
1990	4.9504
1995	5.64567
2000	5.34466
2005	5.01784
2010	5.05368
2015	4.75037
2020	4.59667
2025	4.47851
2030	4.42569
2035	4.40013
2040	4.38383
2045	4.36881
2050	4.37108
2055	4.38874
2060	4.41933
2065	4.45716
2070	4.48418
2075	4.48879
2080	4.48018
2085	4.46424
2090	4.45001
2095	4.43857
2100	4.42287