condition mean min max ZT0-3 6.748279999999999 6.748279999999999 6.748279999999999 ZT4-7 7.95847 7.95847 7.95847 ZT8-11 8.714884999999999 8.714884999999999 8.714884999999999 ZT12-15 5.82217 5.82217 5.82217 ZT16-19 4.14794 4.14794 4.14794 ZT20-23 4.741815 4.741815 4.741815