condition mean min max ZT0-3 35.035581 35.035581 35.035581 ZT4-7 33.147478 33.147478 33.147478 ZT8-11 38.3799995 38.3799995 38.3799995 ZT12-15 39.747802500000006 39.747802500000006 39.747802500000006 ZT16-19 45.773050999999995 45.773050999999995 45.773050999999995 ZT20-23 37.488378499999996 37.488378499999996 37.488378499999996