| Year | Value | | 2021 | 13.243075525657 | | 2020 | -26.478151091843 | | 2019 | 2.2696414793642 | | 2018 | -1.8204293928664 | | 2017 | 5.7022596965271 | | 2016 | 0.28633299656231 | | 2015 | 3.4897777226887 | | 2014 | 2.3412744265354 | | 2013 | -3.5213620304244 | | 2012 | 0.10907734794701 | | 2011 | -1.8903421246977 | | 2010 | -2.8674361437768 | | 2009 | -9.5589418709024 | | 2008 | -3.1640482478022 | | 2007 | 4.4200431955259 | | 2006 | -3.0742833670738 | | 2005 | 4.7164616063967 | | 2004 | -2.8479646179518 | | 2003 | -2.1458214785072 | | 2002 | 10.872672644227 | | 2001 | -2.6381014159485 | | 2000 | 4.3665227517989 | | 1999 | 10.389032279052 | | 1998 | 8.0401734884722 | | 1997 | 6.9121755460671 | | 1996 | 13.222694366886 | | 1995 | 22.859868452076 | | 1994 | 1.9228682303828 | | 1993 | -2.5623932912722 | | 1992 | 0.67507105613704 | | 1991 | -6.5693918589728 | | 1990 | -1.7912645054537 |
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