condition mean min max ZT0-3 8.947775 8.947775 8.947775 ZT4-7 5.954610000000001 5.954610000000001 5.954610000000001 ZT8-11 9.569885 9.569885 9.569885 ZT12-15 13.657250000000001 13.657250000000001 13.657250000000001 ZT16-19 11.95185 11.95185 11.95185 ZT20-23 9.550145 9.550145 9.550145