condition mean min max ZT0-3 268.111706 268.111706 268.111706 ZT4-7 439.16601149999997 439.16601149999997 439.16601149999997 ZT8-11 407.1541655 407.1541655 407.1541655 ZT12-15 495.810335 495.810335 495.810335 ZT16-19 207.04362099999997 207.04362099999997 207.04362099999997 ZT20-23 80.52729149999999 80.52729149999999 80.52729149999999