user: Question: What is the number of riders that had a Tues 31 May time of 18' 55.91 124.236mph?
Columns: ['Rank', 'Rider', 'Mon 30 May', 'Tues 31 May', 'Wed 1 June', 'Thurs 2 June', 'Fri 3 June']
Types: ['real', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: [1.0, 'Michael Dunlop 600cc Yamaha', '—— No Time', "18' 02.60 125.462mph", '—— No Time', 'Cancelled No Time', "18' 04.32 125.266mph"]
SQL:

assistant: SELECT COUNT("Rider") FROM "Table" WHERE "Tues 31 May" = '18'' 55.91 124.236mph';