Table:
text: Nagoya Municipal Subway
Lines and infrastructure
Lines and infrastructure
Color_Icon Name__1 Name__2 Mark First_section_opened Last_ex_tension Length_ Stations_
yellow Line 1 Higashiyama Line H 1957 1982 20.6 km (12.8 mi) 22
purple Line 2 Meijō Line M 1965 1971 8.9 km (5.5 mi) 12
purple Line 4 Meijō Line M 1974 2004 17.5 km (10.9 mi) 17
purple & white Line 2 Meikō Line E 1971 - 6.0 km (3.7 mi) 7
blue Via trackage rights Meitetsu Inuyama Line - 1993 - 21.4 km (13.3 mi) 13
blue Line 3 Tsurumai Line T 1977 1993 20.4 km (12.7 mi) 20
blue Via trackage rights Meitetsu Toyota Line - 1979 - 15.2 km (9.4 mi) 8

Question: How long is the Higashiyama Line on the Nagoya Municipal Subway?