user: Question: What is listed under the Years as tallest, that has Floors of 31?
Columns: ['Name', 'City', 'Years as tallest', 'Metres', 'Feet', 'Floors']
Types: ['text', 'text', 'text', 'real', 'real', 'real']
Sample row: ['Carlton Centre', 'Johannesburg', '1973–present', 223.0, 732.0, 50.0]
SQL:

assistant: SELECT "Years as tallest" FROM "Table" WHERE "Floors" = 31.0;