condition mean min max ZT0-3 12.1024081455 10.805486681000001 13.39932961 ZT4-7 10.687533400166666 8.488004834 12.887061966333333 ZT8-11 20.530645305 17.54728881 23.5140018 ZT12-15 9.011329975333334 6.631785895 11.390874055666668 ZT16-19 6.270540794666667 5.049397965 7.491683624333334 ZT20-23 2.9335789205 2.317129533666667 3.550028307333333