condition mean min max ZT0-3 6.347783333333333 4.85063 7.49103 ZT4-7 4.742795 4.742795 4.742795 ZT8-11 5.569655 5.569655 5.569655 ZT12-15 12.289575000000001 12.210650000000001 12.368500000000001 ZT16-19 12.49385 12.49385 12.49385 ZT20-23 11.551929999999999 11.551929999999999 11.551929999999999