condition mean min max ZT0-3 34.687475 33.9608 35.41415 ZT4-7 27.086799999999997 27.086799999999997 27.086799999999997 ZT8-11 39.52095 39.52095 39.52095 ZT12-15 0 0 0 ZT16-19 39.836600000000004 39.836600000000004 39.836600000000004 ZT20-23 37.799099999999996 37.799099999999996 37.799099999999996