| Year | Value | | 2022 | 1.3507786358357 | | 2021 | 1.7335396269405 | | 2020 | 3.0227211966369 | | 2019 | 0.70502663454272 | | 2018 | 0.64480362244075 | | 2017 | 1.7694124739201 | | 2016 | 0.79405017390647 | | 2015 | 0.21878592353597 | | 2014 | 0.54875755094791 | | 2013 | 0.42888888888824 | | 2012 | 6.7446825334075 | | 2011 | 2.7042390774728 | | 2010 | 2.2078353253652 | | 2009 | 0.89607235574905 | | 2008 | 7.9472987606786 | | 2007 | 1.2980681333415 | | 2006 | 3.7821769654038 | | 2005 | 5.3645208583234 | | 2004 | 0.87389083086851 | | 2003 | 1.4872424614544 | | 2002 | 2.4891623549154 | | 2001 | 3.9842954776789 | | 2000 | 4.1654044229028 | | 1999 | 0.32672289339687 | | 1998 | 5.7533145841706 | | 1997 | 3.4662959056478 | | 1996 | 4.914239726372 | | 1995 | 14.462548218089 | | 1994 | 38.530866166854 | | 1993 | 0.44059921493179 |
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