condition mean min max ZT0-3 3.81097 3.81097 3.81097 ZT4-7 1.97935 1.97935 1.97935 ZT8-11 5.726065 5.726065 5.726065 ZT12-15 11.131905 11.131905 11.131905 ZT16-19 13.133299999999998 13.133299999999998 13.133299999999998 ZT20-23 7.278565 7.278565 7.278565