condition mean min max ZT0-3 8.661797 8.661797 8.661797 ZT4-7 8.844245 8.844245 8.844245 ZT8-11 8.267962 8.267962 8.267962 ZT12-15 9.362025500000001 9.362025500000001 9.362025500000001 ZT16-19 7.949209 7.949209 7.949209 ZT20-23 8.958311 8.958311 8.958311