condition mean min max ZT0-3 3.867335 3.6516900000000003 4.08298 ZT4-7 4.78279 4.78279 4.78279 ZT8-11 5.236845 5.236845 5.236845 ZT12-15 0 0 0 ZT16-19 5.88918 5.88918 5.88918 ZT20-23 4.303405 4.303405 4.303405