condition mean min max ZT0-3 5.6082775 4.67181 6.544745 ZT4-7 3.60386 3.60386 3.60386 ZT8-11 3.68959 3.68959 3.68959 ZT12-15 0 0 0 ZT16-19 4.626720000000001 4.626720000000001 4.626720000000001 ZT20-23 5.953915 5.953915 5.953915