condition mean min max ZT0-3 0.7835318333333334 0.6732295 0.9277040000000001 ZT4-7 0.8102845000000001 0.8102845000000001 0.8102845000000001 ZT8-11 6.81302 6.81302 6.81302 ZT12-15 7.211080000000001 5.670915 8.751245 ZT16-19 4.04649 4.04649 4.04649 ZT20-23 1.1363625 1.1363625 1.1363625