condition mean min max ZT0-3 15.6767 15.6767 15.6767 ZT4-7 9.424795 9.424795 9.424795 ZT8-11 12.2286 12.2286 12.2286 ZT12-15 16.60125 16.60125 16.60125 ZT16-19 17.95495 17.95495 17.95495 ZT20-23 15.748999999999999 15.748999999999999 15.748999999999999