condition mean min max ZT0-3 10.6979075 8.710564999999999 12.68525 ZT4-7 16.74105 16.74105 16.74105 ZT8-11 28.3906 28.3906 28.3906 ZT12-15 0 0 0 ZT16-19 21.6844 21.6844 21.6844 ZT20-23 20.01275 20.01275 20.01275