Year Number 1996 100 1998 100 2000 98.9417953491211 2002 99.4709014892578 2003 98.9949722290039 2004 99.0291290283203 2005 99.0291290283203 2006 98.5507278442383 2007 96.6183547973633 2008 98.5576934814453 2009 92.890998840332 2010 99.052131652832 2011 99.052131652832 2012 98.5782012939453 2013 99.052131652832 2014 97.1428604125977 2015 97.6190490722656 2016 98.0952377319336 2017 97.6190490722656 2018 99.5283050537109 2019 97.6415100097656 2020 98.5849075317383 2021 97.6415100097656 2022 97.6415100097656