condition mean min max ZT0-3 8.33675 8.33675 8.33675 ZT4-7 8.725782500000001 8.725782500000001 8.725782500000001 ZT8-11 7.7358645 7.7358645 7.7358645 ZT12-15 8.4751485 8.4751485 8.4751485 ZT16-19 8.200447 8.200447 8.200447 ZT20-23 8.3771325 8.3771325 8.3771325