Year	Percent
1991	5.706
1992	5.524
1993	5.339
1994	5.295
1995	5.255
1996	5.006
1997	4.9
1998	4.826
1999	5.446
2000	5.055
2001	5.79
2002	6.487
2003	6.786
2004	7.035
2005	6.731
2006	6.59
2007	6.127
2008	6.238
2009	6.284
2010	5.368
2011	5.81
2012	5.697
2013	5.632
2014	5.263
2015	5.324
2016	5.348
2017	5.424
2018	5.425
2019	5.427
2020	5.428
2021	5.43
2022	5.431
