condition mean min max ZT0-3 41.39868763 30.50286634 52.29450892 ZT4-7 12.64030646025 11.89886105 13.3817518705 ZT8-11 18.208515114999997 13.533710995 22.883319235 ZT12-15 19.191144265 17.411872085 20.970416445 ZT16-19 14.0697635545 12.811797744 15.327729365 ZT20-23 9.89293778025 9.2489213695 10.536954191