condition mean min max ZT0-3 7.60921 7.60921 7.60921 ZT4-7 4.4807749999999995 4.4807749999999995 4.4807749999999995 ZT8-11 7.528555000000001 7.528555000000001 7.528555000000001 ZT12-15 14.3098 14.3098 14.3098 ZT16-19 13.875499999999999 13.875499999999999 13.875499999999999 ZT20-23 9.086003333333334 9.086003333333334 9.086003333333334