condition mean min max ZT0-3 0.626985 0.626985 0.626985 ZT4-7 1.158985 1.158985 1.158985 ZT8-11 0.4713305 0.4713305 0.4713305 ZT12-15 3.160095 3.160095 3.160095 ZT16-19 2.282315 2.282315 2.282315 ZT20-23 1.1257389999999998 1.1257389999999998 1.1257389999999998