user: Question: Name the total number for period of validity for Upper Volta
Columns: ['Former country name', 'Former codes', 'Period of validity', 'ISO 3166-3 code', 'New country names and codes']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['British Antarctic Territory', 'BQ , ATB , 080', '1974–1979', 'BQAQ', 'Merged into Antarctica ( AQ , ATA , 010 )']
SQL:

assistant: SELECT COUNT("Period of validity") FROM "Table" WHERE "Former country name" = 'Upper Volta';