condition mean min max ZT0-3 20.65012 20.65012 20.65012 ZT4-7 22.799285 22.799285 22.799285 ZT8-11 34.8109215 34.8109215 34.8109215 ZT12-15 26.160438999999997 26.160438999999997 26.160438999999997 ZT16-19 87.53291300000001 87.53291300000001 87.53291300000001 ZT20-23 53.677818 53.677818 53.677818