condition mean min max ZT0-3 14.95215 14.95215 14.95215 ZT4-7 16.3183675 16.3183675 16.3183675 ZT8-11 12.340477 12.340477 12.340477 ZT12-15 10.3485055 10.3485055 10.3485055 ZT16-19 9.730831 9.730831 9.730831 ZT20-23 10.8187475 10.8187475 10.8187475