condition mean min max ZT0-3 9.267981666666666 7.1026299999999996 10.37524 ZT4-7 8.394625 8.394625 8.394625 ZT8-11 6.24075 6.24075 6.24075 ZT12-15 9.7991825 6.156065 13.4423 ZT16-19 12.4413 12.4413 12.4413 ZT20-23 15.7733 15.7733 15.7733