SELECT COUNT("Voivodeship") FROM table_17008 WHERE "Population (1980)" = '747 900'
How many different voivodenship have 747 900 citizes?
CREATE TABLE table_17008 (
    "Abbreviation" text,
    "Voivodeship" text,
    "Capital" text,
    "Area km\u00b2 (1998)" text,
    "Population (1980)" text,
    "No. of cities" real,
    "No. of communes" real
)