condition mean min max ZT0-3 12.406134 12.406134 12.406134 ZT4-7 11.990459 11.990459 11.990459 ZT8-11 11.3985165 11.3985165 11.3985165 ZT12-15 10.2738175 10.2738175 10.2738175 ZT16-19 11.3092125 11.3092125 11.3092125 ZT20-23 8.969047499999999 8.969047499999999 8.969047499999999