There are 37 bosses in Dark Souls 2, including all 3 DLC. (not counting the challenge bosses)

14 of those are ganks, and 8 of those are either re-skins of previous bosses or are used as late-game enemies.

That means 38% of all bosses in Dark Souls 2 are Ganks.

We also learn that aproximately 22% of bosses that are re-skins or used as late-game enemies.

Now let's crunch those same numbers in Dark Souls 1.

There are 27 bosses (including hydra) in Dark Souls 1, and 11 of them are ganks.That gives us 41%. 41% of all bosses in DS1 were ganks. That's 3% MORE than Dark Souls II. Taking a similar look at the numbers for re-used bosses, we find out that 30% of all bosses in Dark Souls 1 were either re-skins or re-used as late game mobs. That's a total of 8% more than Dark Souls II.

Even counting the three optional DLC challenge bosses, we get a total of 35% gank bosses and 28% re-skins/re-used bosses. That brings Dark Souls II even for ganks with Dark Souls 1 and gives it 1% more gank bosses. So, if anyone ever tries to tell you again that Dark Souls 2 is just filled to the brim with re-skins and gank bosses, take these statistics and give them a big jolly slap in the face.