condition mean min max ZT0-3 8.130646 8.130646 8.130646 ZT4-7 11.651693999999999 11.651693999999999 11.651693999999999 ZT8-11 13.2092715 13.2092715 13.2092715 ZT12-15 11.099993999999999 11.099993999999999 11.099993999999999 ZT16-19 10.06984 10.06984 10.06984 ZT20-23 8.644439 8.644439 8.644439