condition mean min max ZT0-3 5.90344 5.90344 5.90344 ZT4-7 2.089785 2.089785 2.089785 ZT8-11 7.9627300000000005 7.9627300000000005 7.9627300000000005 ZT12-15 11.942235 11.942235 11.942235 ZT16-19 13.6312 13.6312 13.6312 ZT20-23 9.31447 9.31447 9.31447