condition mean min max ZT0-3 6.3648925 5.9924 6.737385 ZT4-7 6.041945 6.041945 6.041945 ZT8-11 4.5599050000000005 4.5599050000000005 4.5599050000000005 ZT12-15 0 0 0 ZT16-19 6.509285 6.509285 6.509285 ZT20-23 8.01408 8.01408 8.01408