user: Question: What is the longest length of mandatory secondary school?
Columns: ['Canton', 'Years of Kindergarten', 'Years of Kindergarten provided', 'Years of Kindergarten legally required', 'Length of Primary School', 'Length of mandatory Secondary School', 'Separate Secondary Schools?', 'Cooperative Secondary Schools?', 'Integrated Secondary Schools?']
Types: ['text', 'real', 'text', 'text', 'real', 'real', 'text', 'text', 'text']
Sample row: ['Zurich', 2.0, '2', '2', 6.0, 3.0, 'Yes', 'No', 'No']
SQL:

assistant: SELECT MAX("Length of mandatory Secondary School") FROM "Table";