condition mean min max ZT0-3 14.497825 12.0093 16.98635 ZT4-7 10.77862 10.77862 10.77862 ZT8-11 8.668795 8.668795 8.668795 ZT12-15 0 0 0 ZT16-19 15.3201 15.3201 15.3201 ZT20-23 10.72406 10.72406 10.72406