user: Question: What is the total number of Year(s), when Tournament is "world championships"?
Columns: ['Year', 'Tournament', 'Venue', 'Result', 'Extra']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [2000.0, 'World Junior Championships', 'Santiago , Chile', '7th', 'Heptathlon']
SQL:

assistant: SELECT COUNT("Year") FROM "Table" WHERE "Tournament" = 'world championships';