condition mean min max ZT0-3 2.1051136085 1.667570096 2.5426571209999995 ZT4-7 2.39884697775 2.1913908070000003 2.6063031485 ZT8-11 2.64284580925 2.1868944165 3.098797202 ZT12-15 5.920424161000001 5.050702447000001 6.790145875 ZT16-19 7.405440007499999 7.163324895 7.64755512 ZT20-23 9.3713305085 9.099842989999999 9.642818027