"The premine block was mined yesterday and sent to Bittrex, and right now 7202 blocks will be mined until the launch with 0 reward during the ICO to maintain the blockchain working."How can be that we are on the block 4917 if they mined 7202 blocks?

Block 1: premine
Blocks 2-5000: 0 reward
Blocks 5001-5100: 10 reward
Blocks 5101-15098: 500 reward
Block 15099: 0 reward (end POW)
You can see it in this chart:
http://i.imgur.com/4u24BEs.png