condition mean min max ZT0-3 301.565582 301.565582 301.565582 ZT4-7 252.1017835 252.1017835 252.1017835 ZT8-11 259.739773 259.739773 259.739773 ZT12-15 285.5616955 285.5616955 285.5616955 ZT16-19 245.9952725 245.9952725 245.9952725 ZT20-23 293.3252765 293.3252765 293.3252765