condition mean min max ZT0-3 13.007545 7.339735 17.4887 ZT4-7 5.025765 5.025765 5.025765 ZT8-11 5.96969 5.96969 5.96969 ZT12-15 13.403075000000001 12.513950000000001 14.292200000000001 ZT16-19 14.91415 14.91415 14.91415 ZT20-23 21.074550000000002 21.074550000000002 21.074550000000002