user: Question: What is the Series leader with a Date that is May 31?
Columns: ['Date', 'Event', 'Winner', 'Team', 'Series leader']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['February 24', 'Tour du Haut Var', 'Davide Rebellin ( ITA )', 'Gerolsteiner', 'Rinaldo Nocentini ( ITA )']
SQL:

assistant: SELECT "Series leader" FROM "Table" WHERE "Date" = 'May 31';