condition mean min max ZT0-3 5.746876666666667 4.68116 7.06681 ZT4-7 4.279485 4.279485 4.279485 ZT8-11 3.0995850000000003 3.0995850000000003 3.0995850000000003 ZT12-15 5.675855 3.3287649999999998 8.022945 ZT16-19 7.11182 7.11182 7.11182 ZT20-23 7.41281 7.41281 7.41281