Year	Percent
1997	1.33691
1998	1.214
1999	1.15124
2000	1.15056
2001	1.12926
2002	0.97371
2003	1.12105
2004	1.26548
2005	1.15051
2006	1.00949
2007	1.07512
2008	1.053
2009	0.96029
2010	1.02944
2011	1.20056
2012	1.14933
2013	1.32108
2014	1.17207
2015	1.03393
2016	0.94264
2017	0.94687
2018	0.9039
2019	0.83881
2020	0.94885
2021	0.95957