condition mean min max ZT0-3 1.979285 1.979285 1.979285 ZT4-7 1.026647 1.026647 1.026647 ZT8-11 1.796055 1.796055 1.796055 ZT12-15 2.023025 2.023025 2.023025 ZT16-19 4.26451 4.26451 4.26451 ZT20-23 2.71421 2.71421 2.71421