condition mean min max ZT0-3 15.363725 13.712700000000002 17.01475 ZT4-7 5.898565 5.898565 5.898565 ZT8-11 3.127659 3.127659 3.127659 ZT12-15 0 0 0 ZT16-19 4.852885000000001 4.852885000000001 4.852885000000001 ZT20-23 7.182835 7.182835 7.182835