condition mean min max ZT0-3 7.3151399999999995 7.3151399999999995 7.3151399999999995 ZT4-7 6.50089 6.50089 6.50089 ZT8-11 5.317945 5.317945 5.317945 ZT12-15 5.37998 5.37998 5.37998 ZT16-19 7.90315 7.90315 7.90315 ZT20-23 8.266774999999999 8.266774999999999 8.266774999999999