user: Question: What is the number of commanders that had 0 off 63 men killed?
Columns: ['Unit', 'Commander', 'Complement', 'Killed', 'Wounded', 'Missing']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['I Corps', 'Major General HRH Prince Willem of Orange GCB', '1300 off 25403 men, 52 guns', '82 off 1192 men', '238 off 4827 men', '12 off 1898 men']
SQL:

assistant: SELECT COUNT("Commander") FROM "Table" WHERE "Killed" = '0 off 63 men';