condition mean min max ZT0-3 18.037325 16.9895 19.08515 ZT4-7 26.79435 26.79435 26.79435 ZT8-11 27.4059 27.4059 27.4059 ZT12-15 0 0 0 ZT16-19 30.74195 30.74195 30.74195 ZT20-23 27.545450000000002 27.545450000000002 27.545450000000002