condition mean min max ZT0-3 6.703865 6.703865 6.703865 ZT4-7 4.700335 4.700335 4.700335 ZT8-11 4.06956 4.06956 4.06956 ZT12-15 4.565765 4.565765 4.565765 ZT16-19 9.00205 9.00205 9.00205 ZT20-23 7.67412 7.67412 7.67412