condition mean min max ZT0-3 1.0862703333333332 0.546421 1.4006349999999999 ZT4-7 0.415493 0.415493 0.415493 ZT8-11 0.9660225 0.9660225 0.9660225 ZT12-15 0.99370125 0.8851355 1.1022669999999999 ZT16-19 1.523005 1.523005 1.523005 ZT20-23 1.71403 1.71403 1.71403