condition mean min max ZT0-3 2.84951 2.84951 2.84951 ZT4-7 2.4447799999999997 2.4447799999999997 2.4447799999999997 ZT8-11 2.5142100000000003 2.5142100000000003 2.5142100000000003 ZT12-15 3.2288449999999997 3.2288449999999997 3.2288449999999997 ZT16-19 4.95682 4.95682 4.95682 ZT20-23 3.70934 3.70934 3.70934