condition mean min max ZT0-3 3.1273375 2.5533349999999997 3.70134 ZT4-7 7.58075 7.58075 7.58075 ZT8-11 2.42456 2.42456 2.42456 ZT12-15 0 0 0 ZT16-19 2.14687 2.14687 2.14687 ZT20-23 5.41016 5.41016 5.41016