condition mean min max ZT0-3 25.899825 25.4965 26.303150000000002 ZT4-7 13.472000000000001 13.472000000000001 13.472000000000001 ZT8-11 10.24614 10.24614 10.24614 ZT12-15 0 0 0 ZT16-19 20.524900000000002 20.524900000000002 20.524900000000002 ZT20-23 21.5081 21.5081 21.5081