Year	Percent
1997	2.1395
1998	2.16737
1999	2.19621
2000	2.09165
2001	2.11789
2002	1.98762
2003	2.05309
2004	2.16781
2005	1.88031
2006	1.70102
2007	1.58716
2008	1.76827
2009	1.54989
2010	1.49324
2011	1.76566
2012	1.81135
2013	1.89423
2014	1.58655
2015	1.86984
2016	1.86223
2017	1.88999
2018	1.69989
2019	1.69708