condition mean min max ZT0-3 5.9320450000000005 5.828965 6.035125 ZT4-7 4.71111 4.71111 4.71111 ZT8-11 4.17918 4.17918 4.17918 ZT12-15 0 0 0 ZT16-19 5.472265 5.472265 5.472265 ZT20-23 5.759685 5.759685 5.759685