condition mean min max ZT0-3 11.487188 11.487188 11.487188 ZT4-7 13.8992 13.8992 13.8992 ZT8-11 18.622425 18.622425 18.622425 ZT12-15 19.5097115 19.5097115 19.5097115 ZT16-19 17.7568645 17.7568645 17.7568645 ZT20-23 16.3894735 16.3894735 16.3894735