user: Question: How many nationalities/sponsors for mirror/type Schmidt UV?
Columns: ['Name', 'Aperture m', 'Aper. in', 'Mirror/type', 'Nationality/Sponsors', 'Site', 'Built/Used']
Types: ['text', 'text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Hopkins Ultraviolet Telescope', '90cm', '35.4″', 'Single UV', 'USA', 'STS , Earth Orbit', '1990, 1995']
SQL:

assistant: SELECT COUNT("Nationality/Sponsors") FROM "Table" WHERE "Mirror/type" = 'Schmidt UV';