condition mean min max ZT0-3 13.879075 13.3496 14.40855 ZT4-7 8.713195 8.713195 8.713195 ZT8-11 9.792935 9.792935 9.792935 ZT12-15 0 0 0 ZT16-19 34.26705 34.26705 34.26705 ZT20-23 16.60755 16.60755 16.60755