just opened a few vote crates (524), noted how many of each item I won in the crate, and figured out rough drop percentages. I didn't receive a pig spawner so I don't have a value for that, just assume it to be very low (or myself 'unlucky'..) 2 vote keys: 2% Common key: 4% Pig: ? Chicken spawner: 1.5% Squid spawner: 0.2% 10 XP: 8% 20 XP: 7% 10 diamonds: 5.7% 16 gold: 6% 16 iron: 5% 64 coal: 6.5% 5 mcmmo: 7% 10 mcmmo: 5% $1000: 7% $1500: 7% $2000: 8% $2500: 4.5% $3000: 5.7% $5000: 3.6% 25 sell wand: 5.7% 1) I will have made slight errors, 2) the percentages together run short of 100 (see 1), 3) There isn't much use of this, just felt like doing it :')
It's a coincidence you posted this, I was planning on doing something like this (I had a spreadsheet and percentages and everything) but then never got around to it, now I'm curious to see how your luck compared to mine (I can't remember exactly how many but I remember I opened over 1,000)
The plan was to start with an initial 1000 for the vote crate, eventually saving to replicate this with the other crates, but the opening as opposed to the acquiring of the keys (at least in the case of vote keys) proved pretty painful... I'd encourage you to uptake this yourself should you want more accurate results though!