condition mean min max ZT0-3 2.90042 2.4134599999999997 3.3873800000000003 ZT4-7 3.781555 3.781555 3.781555 ZT8-11 4.2219999999999995 4.2219999999999995 4.2219999999999995 ZT12-15 0 0 0 ZT16-19 6.34894 6.34894 6.34894 ZT20-23 4.5897 4.5897 4.5897