condition mean min max ZT0-3 4.029823333333334 3.44318 4.65472 ZT4-7 4.244275 4.244275 4.244275 ZT8-11 4.56975 4.56975 4.56975 ZT12-15 9.28639 8.81574 9.75704 ZT16-19 6.05273 6.05273 6.05273 ZT20-23 4.994185 4.994185 4.994185