Year	total route-km
1980	437002.9
1981	436779.9
1982	438601.9
1983	439575.9
1984	439786.9
1985	443227.9
1986	444086.4
1987	443455.4
1988	444105.4
1989	447395.4
1990	453595.063
1991	449491.4
1992	448458
1993	449285.1
1994	448986.9
1995	447066
1996	453229.222105263
1997	454453.7
1998	455095
1999	455278.34
2000	458389
2001	455695
2002	454624
2003	452434
2004	451997
2005	482624
2006	483932
2007	487545
2008	485296
2009	477318
2010	479685
2011	481239
2012	480929
2013	480079.94
2014	484705
2015	483233.82
2016	483608.15