Apparently over 1/4 million in the largest collection.
First reaction is "How the beep do you end up with 1/4 million, presumably, unique designs?". Even if a lot are variations on the themes of "Fred Bloggs' Superstrong Cheese".
Second reaction is "How the beep does anyone find the time to locate, collect and catalogue 1/2 million labels." At 12 hours a day thats around one a minute for a year. Um "Does not compute!"
Clive