condition mean min max ZT0-3 1.9665783333333333 0.0 3.524 ZT4-7 0.552815 0.552815 0.552815 ZT8-11 2.24499 2.24499 2.24499 ZT12-15 0.83476 0.53142 1.1381 ZT16-19 2.5604449999999996 2.5604449999999996 2.5604449999999996 ZT20-23 2.55857 2.55857 2.55857