condition mean min max ZT0-3 1.641995 1.5390100000000002 1.74498 ZT4-7 2.336075 2.336075 2.336075 ZT8-11 2.07418 2.07418 2.07418 ZT12-15 0 0 0 ZT16-19 2.547145 2.547145 2.547145 ZT20-23 2.115555 2.115555 2.115555