condition mean min max ZT0-3 6.625235 5.614275 7.44605 ZT4-7 6.139519999999999 6.139519999999999 6.139519999999999 ZT8-11 4.159385 4.159385 4.159385 ZT12-15 4.7652775 4.302295 5.22826 ZT16-19 4.619645 4.619645 4.619645 ZT20-23 7.026529999999999 7.026529999999999 7.026529999999999