condition mean min max ZT0-3 12.502283 12.502283 12.502283 ZT4-7 10.79409 10.79409 10.79409 ZT8-11 10.8183715 10.8183715 10.8183715 ZT12-15 10.492497499999999 10.492497499999999 10.492497499999999 ZT16-19 12.2302515 12.2302515 12.2302515 ZT20-23 11.9833 11.9833 11.9833