condition mean min max ZT0-3 22.95635 20.7084 25.2043 ZT4-7 6.09012 6.09012 6.09012 ZT8-11 8.884105 8.884105 8.884105 ZT12-15 0 0 0 ZT16-19 19.42185 19.42185 19.42185 ZT20-23 11.86035 11.86035 11.86035