condition mean min max ZT0-3 11.533945 11.533945 11.533945 ZT4-7 9.8763375 9.8763375 9.8763375 ZT8-11 10.832723000000001 10.832723000000001 10.832723000000001 ZT12-15 11.6490555 11.6490555 11.6490555 ZT16-19 9.6071355 9.6071355 9.6071355 ZT20-23 10.6229305 10.6229305 10.6229305