Yeat	Density
2001	54.18857327
2002	54.90041462
2003	55.58595231
2004	56.26767664
2005	56.96228092
2006	57.6746799
2007	58.40161475
2008	59.14145889
2009	59.88978729
2010	60.64271406
2011	61.40139047
2012	62.16593894
2013	62.92980735