condition mean min max ZT0-3 28.636675 27.7513 29.52205 ZT4-7 35.51875 35.51875 35.51875 ZT8-11 34.62335 34.62335 34.62335 ZT12-15 0 0 0 ZT16-19 29.868650000000002 29.868650000000002 29.868650000000002 ZT20-23 43.5941 43.5941 43.5941