Ok, so done the same for attack..
Just spent hours trying to work out Excel and get the tables like I did for the HP, but I'm failing and can't remember how I did it.....here is the data, anyone who can make a nice looking chart out of it, that'd be awesome! If you do you're also welcome to make it look great for the HP, I can give values etc if needed, I'm just rubbish at using Excel and making it look good, sorry...
NB: percentage should actually be approx percentage.
Also, once again not included rare creatures or flying weapons.
Oh, also forgot to mention - creatures with attack 'growth'. Again I've used original attack value for the data.
Lycanthrope, Vulture, Otyugh, Grav. Fire Eater, Graboid, Forest Spirit, Fire Spectre, Lava Golem, Steam Machine, Pegasus, Crusader, Wyrm, Fate Egg, Scarab, and arguably Fallen Elf