condition mean min max ZT0-3 2.247046666666667 1.483355 3.1600200000000003 ZT4-7 1.3893550000000001 1.3893550000000001 1.3893550000000001 ZT8-11 2.08776 2.08776 2.08776 ZT12-15 9.09376 7.79699 10.39053 ZT16-19 7.999525 7.999525 7.999525 ZT20-23 5.862465 5.862465 5.862465