user: Question: What is the total number of Year of Intro(s), when Country of Origin is soviet union, when Type is reusable, when Primary Cartridge is 40mm, and when Name/ Designation is rpg-29?
Columns: ['Name/ designation', 'Year of intro', 'Country of origin', 'Primary cartridge', 'Type']
Types: ['text', 'real', 'text', 'text', 'text']
Sample row: ['M1 Bazooka', 1942.0, 'United States', '60mm', 'Recoilless']
SQL:

assistant: SELECT COUNT("Year of intro") FROM "Table" WHERE "Country of origin" = 'soviet union' AND "Type" = 'reusable' AND "Primary cartridge" = '40mm' AND "Name/ designation" = 'rpg-29';