condition mean min max ZT0-3 16.35345 16.35345 16.35345 ZT4-7 21.58115 21.58115 21.58115 ZT8-11 13.9588 13.9588 13.9588 ZT12-15 13.3153 13.3153 13.3153 ZT16-19 11.97775 11.97775 11.97775 ZT20-23 11.9848 11.9848 11.9848