Year	total route-km
1980	72779
1981	72635
1982	73775
1983	73505
1984	73292
1985	73109
1986	73347.5
1987	72812.5
1988	72868.5
1989	77523.5
1990	77118.1
1991	77022.1
1992	77123.1
1993	77163.4
1994	76577.2
1995	76390.3
1996	82419.02
1997	81951
1998	81951
1999	81951
2000	81891
2001	81598
2002	81303
2003	81305
2004	80967
2005	108664
2006	108570
2007	108743
2008	108447
2009	97207
2010	97207
2011	97284
2012	97293
2013	97293
2014	97384
2015	97384
2016	97384