condition mean min max ZT0-3 13.309937 13.309937 13.309937 ZT4-7 12.75389 12.75389 12.75389 ZT8-11 12.7381435 12.7381435 12.7381435 ZT12-15 12.341114000000001 12.341114000000001 12.341114000000001 ZT16-19 12.5572485 12.5572485 12.5572485 ZT20-23 12.321253500000001 12.321253500000001 12.321253500000001