Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Color & Icon | Name | Name | Mark | First section\nopened | Last ex-\ntension | 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 |
| blue | Via trackage rights | Meitetsu Mikawa Line | - | N/A | - | 1.4 km (0.87 mi) | 2 |
| red | Line 6 | Sakura-dōri Line | S | 1989 | 2011 | 19.1 km (11.9 mi) | 21 |
| pink | Via trackage rights | Meitetsu Komaki Line | - | 2003 | - | 18.3 km (11.4 mi) | 13 |
| pink | Via trackage rights | Meitetsu Komaki Line | - | 2003 | - | 2.3 km (1.4 mi) | 2 |
| pink | Line 7 | Kamiiida Line | K | 2003 | - | 0.8 km (0.50 mi) | 2 |
Question:
how many lines exist in total?
Answer:
7