condition mean min max ZT0-3 8.472543333333334 6.91386 9.74732 ZT4-7 5.47581 5.47581 5.47581 ZT8-11 1.611615 1.611615 1.611615 ZT12-15 2.607095 2.367835 2.846355 ZT16-19 2.066125 2.066125 2.066125 ZT20-23 3.697575 3.697575 3.697575