condition mean min max ZT0-3 6.81184 4.57209 9.051590000000001 ZT4-7 6.33334 6.33334 6.33334 ZT8-11 5.330715 5.330715 5.330715 ZT12-15 0 0 0 ZT16-19 4.957055 4.957055 4.957055 ZT20-23 4.49109 4.49109 4.49109