Name the total number for period of validity for upper volta
CREATE TABLE table_73368 (
    "Former country name" text,
    "Former codes" text,
    "Period of validity" text,
    "ISO 3166-3 code" text,
    "New country names and codes" text
)
SELECT COUNT("Period of validity") FROM table_73368 WHERE "Former country name" = 'Upper Volta'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: Name the total number for period of validity for upper volta ### Input: CREATE TABLE table_73368 (
    "Former country name" text,
    "Former codes" text,
    "Period of validity" text,
    "ISO 3166-3 code" text,
    "New country names and codes" text
) ### Response: SELECT COUNT("Period of validity") FROM table_73368 WHERE "Former country name" = 'Upper Volta'