condition mean min max ZT0-3 1.773655 1.773655 1.773655 ZT4-7 1.16818 1.16818 1.16818 ZT8-11 2.08406 2.08406 2.08406 ZT12-15 4.011279999999999 4.011279999999999 4.011279999999999 ZT16-19 2.6986749999999997 2.6986749999999997 2.6986749999999997 ZT20-23 1.947225 1.947225 1.947225