condition mean min max ZT0-3 5.176295 5.176295 5.176295 ZT4-7 4.6728000000000005 4.6728000000000005 4.6728000000000005 ZT8-11 4.44853 4.44853 4.44853 ZT12-15 5.95387 5.95387 5.95387 ZT16-19 5.102595 5.102595 5.102595 ZT20-23 4.767065 4.767065 4.767065