condition mean min max ZT0-3 4.68905 4.68905 4.68905 ZT4-7 3.8251600000000003 3.8251600000000003 3.8251600000000003 ZT8-11 5.817435 5.817435 5.817435 ZT12-15 8.921804999999999 8.921804999999999 8.921804999999999 ZT16-19 6.66622 6.66622 6.66622 ZT20-23 4.83675 4.83675 4.83675