condition mean min max ZT0-3 6.906816666666666 4.788455 9.266539999999999 ZT4-7 7.956575 7.956575 7.956575 ZT8-11 6.9374 6.9374 6.9374 ZT12-15 11.380345 3.41449 19.3462 ZT16-19 14.157205 14.157205 14.157205 ZT20-23 5.798055 5.798055 5.798055