condition mean min max ZT0-3 7.15556 7.15556 7.15556 ZT4-7 8.314928 8.314928 8.314928 ZT8-11 7.495449499999999 7.495449499999999 7.495449499999999 ZT12-15 7.574484 7.574484 7.574484 ZT16-19 7.986717499999999 7.986717499999999 7.986717499999999 ZT20-23 7.8047585 7.8047585 7.8047585