condition mean min max ZT0-3 9.173633333333333 8.79962 9.64257 ZT4-7 8.95335 8.95335 8.95335 ZT8-11 4.977535 4.977535 4.977535 ZT12-15 6.3354775000000005 5.3760200000000005 7.294935000000001 ZT16-19 6.638095 6.638095 6.638095 ZT20-23 10.304915000000001 10.304915000000001 10.304915000000001