condition mean min max ZT0-3 62.973577 62.973577 62.973577 ZT4-7 74.3155535 74.3155535 74.3155535 ZT8-11 65.5869385 65.5869385 65.5869385 ZT12-15 67.2951465 67.2951465 67.2951465 ZT16-19 42.042996 42.042996 42.042996 ZT20-23 36.487046 36.487046 36.487046