condition mean min max ZT0-3 6.3166014925 6.239888178999999 6.393314806 ZT4-7 2.089491508 1.947988167 2.230994849 ZT8-11 3.13884449325 2.3873510225 3.8903379640000004 ZT12-15 5.740774650500001 4.906338051500001 6.5752112495 ZT16-19 5.11957085475 4.6499286355 5.589213074 ZT20-23 8.00098612125 7.885049443 8.1169227995