condition mean min max ZT0-3 613.822341 613.822341 613.822341 ZT4-7 911.9500295 911.9500295 911.9500295 ZT8-11 1070.55898 1070.55898 1070.55898 ZT12-15 838.3979595000001 838.3979595000001 838.3979595000001 ZT16-19 816.2170215 816.2170215 816.2170215 ZT20-23 728.3072665 728.3072665 728.3072665