condition mean min max ZT0-3 19.652075 17.87075 21.4334 ZT4-7 21.79155 21.79155 21.79155 ZT8-11 31.610149999999997 31.610149999999997 31.610149999999997 ZT12-15 0 0 0 ZT16-19 34.723349999999996 34.723349999999996 34.723349999999996 ZT20-23 30.93935 30.93935 30.93935