Year	sq. km
1990	1571405.9
1991	1591265.86
1992	1611125.82
1993	1630985.78
1994	1650845.74
1995	1670705.7
1996	1690565.66
1997	1710425.62
1998	1730285.58
1999	1750145.54
2000	1770005.5
2001	1793615.33
2002	1817225.16
2003	1840834.99
2004	1864444.82
2005	1888054.65
2006	1911664.48
2007	1935274.31
2008	1958884.14
2009	1982493.97
2010	2006103.8
2011	2025471.54
2012	2044839.28
2013	2064207.02
2014	2083574.76
2015	2102942.5
2016	2124598.67
2017	2143394.7
2018	2162190.4
2019	2180986.1
2020	2199781.8
2021	2218577.5