user: Question: How many mens doubles took place in 1970/1971?
Columns: ['Season', 'Mens singles', 'Womens singles', 'Mens doubles', 'Womens doubles', 'Mixed doubles']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['1936/1937', 'Bengt Polling , Malmö BK', 'Thyra Hedvall , SBK', 'Bengt Polling Thore Sjögren , Malmö BK', 'Thyra Hedvall Märtha Sköld , SBK', 'Curt-Eric Walldow Edith Persson , BK-33 Malmö']
SQL:

assistant: SELECT COUNT("Mens doubles") FROM "Table" WHERE "Season" = '1970/1971';