condition mean min max ZT0-3 51.0554 50.5745 51.5363 ZT4-7 34.80275 34.80275 34.80275 ZT8-11 21.24065 21.24065 21.24065 ZT12-15 0 0 0 ZT16-19 37.940799999999996 37.940799999999996 37.940799999999996 ZT20-23 36.453 36.453 36.453