condition mean min max ZT0-3 7.461474999999999 6.8879649999999994 8.034984999999999 ZT4-7 6.202075000000001 6.202075000000001 6.202075000000001 ZT8-11 6.372095 6.372095 6.372095 ZT12-15 0 0 0 ZT16-19 7.0773399999999995 7.0773399999999995 7.0773399999999995 ZT20-23 6.556375 6.556375 6.556375