In the mid-1960s, the United States State Department estimated the party membership to be approximately 1,350,000 (4.2% of the working age population, making it the largest communist party in per capita terms in the capitalist world at the time and the largest party at all in the whole of Western Europe with the German Social Democratic Party). United States government sources have claimed that the party was receiving $40–50 million per year from the Soviets while the United States investment in Italy was $5–6 million. However, declassified information shows this to be exaggerated, although the PCI relied on Soviet financial assistance more than any other communist party supported by Moscow.