condition mean min max ZT0-3 6.8211111110000004 6.8211111110000004 6.8211111110000004 ZT4-7 6.84 6.84 6.84 ZT8-11 7.657222221 7.657222221 7.657222221 ZT12-15 5.547777778 5.547777778 5.547777778 ZT16-19 5.522222222 5.522222222 5.522222222 ZT20-23 4.6899999999999995 4.6899999999999995 4.6899999999999995