Year	years
1960	46.243
1961	46.306
1962	46.283
1963	46.204
1964	46.074
1965	45.89
1966	46.021
1967	46.119
1968	46.269
1969	46.649
1970	46.996
1971	47.283
1972	47.76
1973	48.136
1974	48.516
1975	48.993
1976	49.354
1977	49.883
1978	50.425
1979	51.032
1980	51.724
1981	52.538
1982	53.264
1983	53.804
1984	54.353
1985	54.846
1986	55.164
1987	55.169
1988	55.328
1989	55.425
1990	55.328
1991	55.33
1992	54.611
1993	54.094
1994	54.106
1995	52.944
1996	51.652
1997	50.273
1998	48.707
1999	47.422
2000	46.07
2001	44.774
2002	43.545
2003	42.525
2004	41.609
2005	41.157
2006	40.689
2007	40.811
2008	41.247
2009	42.069
2010	43.214
2011	44.301
2012	45.36
2013	46.428
2014	47.419
2015	48.48
2016	49.564
2017	50.351
2018	50.992
2019	51.406
2020	51.962
2021	50.374
2022	50.319