condition mean min max ZT0-3 20.501242 20.501242 20.501242 ZT4-7 18.625216 18.625216 18.625216 ZT8-11 15.726682499999999 15.726682499999999 15.726682499999999 ZT12-15 23.5927175 23.5927175 23.5927175 ZT16-19 22.210634499999998 22.210634499999998 22.210634499999998 ZT20-23 22.546802999999997 22.546802999999997 22.546802999999997