condition mean min max ZT0-3 6.781111111 6.781111111 6.781111111 ZT4-7 6.487222222 6.487222222 6.487222222 ZT8-11 6.081111111 6.081111111 6.081111111 ZT12-15 5.21 5.21 5.21 ZT16-19 4.537777778 4.537777778 4.537777778 ZT20-23 4.804444444333333 4.804444444333333 4.804444444333333