condition mean min max ZT0-3 1.877735 1.4371 2.1812 ZT4-7 1.3004799999999999 1.3004799999999999 1.3004799999999999 ZT8-11 2.17285 2.17285 2.17285 ZT12-15 5.2372275 4.75689 5.7175650000000005 ZT16-19 4.28336 4.28336 4.28336 ZT20-23 3.83998 3.83998 3.83998