condition mean min max ZT0-3 11.401561666666668 7.715835 14.911900000000001 ZT4-7 6.14481 6.14481 6.14481 ZT8-11 6.4715 6.4715 6.4715 ZT12-15 12.756665000000002 8.787030000000001 16.726300000000002 ZT16-19 9.841275 9.841275 9.841275 ZT20-23 13.00805 13.00805 13.00805