condition mean min max ZT0-3 2.5406263877499997 2.3391254784999997 2.7421272969999997 ZT4-7 1.5487568612499998 1.477484345 1.6200293774999999 ZT8-11 0.66211615625 0.555963503 0.7682688095 ZT12-15 0.7889289500000001 0.6150699385 0.9627879615 ZT16-19 1.7416303704999998 1.2233917475 2.2598689934999996 ZT20-23 5.66545127675 4.350991369 6.979911184500001