Year	total route-km
1980	333254.7
1981	332951.2
1982	333823.3
1983	334028.4
1984	333325.2
1985	333470.9
1986	332770.3
1987	332171.8
1988	331835.8
1989	331564.1
1990	377840.5
1991	380876
1992	377896.7
1993	391796
1994	390022.4
1995	389472
1996	387044.502105263
1997	384223
1998	383051
1999	383953
2000	383461
2001	376215
2002	376592
2003	376660
2004	373574
2005	375805
2006	379704
2007	374677
2008	376106
2009	380800
2010	397564
2011	382492
2012	376486
2013	376377.6
2014	375844
2015	375241.46
2016	377384.22