Although some countries carried 9mm Parabellum, most of FN's sales to law enforcement around Europe was in .32, with a few .380's. I would guess that in order of numbers from high to low and after WWI, the order would be .32, 9mm Parabellum and then .380. Germany' forces were state-operated, and chose various weapons. After WWII, you saw border guards and such with more 9mms, like those Austrian Browning High Powers that were purchased in large numbers.