condition mean min max ZT0-3 4.236300549749999 3.1143354569999997 5.358265642499999 ZT4-7 8.320833810749999 8.304775736 8.3368918855 ZT8-11 6.80265798275 5.8456913805 7.759624585 ZT12-15 9.581569639249999 8.692323857 10.4708154215 ZT16-19 11.81297786575 10.4063947815 13.21956095 ZT20-23 10.44710438075 9.704237483 11.1899712785