condition mean min max ZT0-3 2.6618500000000003 2.6618500000000003 2.6618500000000003 ZT4-7 2.66622 2.66622 2.66622 ZT8-11 2.24224 2.24224 2.24224 ZT12-15 2.5838349999999997 2.5838349999999997 2.5838349999999997 ZT16-19 1.73517 1.73517 1.73517 ZT20-23 2.1950700000000003 2.1950700000000003 2.1950700000000003