condition mean min max ZT0-3 60.905175 42.34355 79.4668 ZT4-7 11.09318 11.09318 11.09318 ZT8-11 4.819425 4.819425 4.819425 ZT12-15 0 0 0 ZT16-19 21.403 21.403 21.403 ZT20-23 32.2663 32.2663 32.2663