user: Question: How many years of introduction does the Neal submachine gun have?
Columns: ['Name/ designation', 'Year of intro', 'Country of origin', 'Primary cartridge', 'Major users']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['CSMG', 2000.0, 'Belgium', '9x19mm Parabellum 22mm Grenade', 'n/a']
SQL:

assistant: SELECT "Year of intro" FROM "Table" WHERE "Name/ designation" = 'Neal submachine gun';