condition mean min max ZT0-3 20.9468 20.9468 20.9468 ZT4-7 14.137250000000002 14.137250000000002 14.137250000000002 ZT8-11 11.10905 11.10905 11.10905 ZT12-15 12.454049999999999 12.454049999999999 12.454049999999999 ZT16-19 20.40345 20.40345 20.40345 ZT20-23 20.2798 20.2798 20.2798