condition mean min max ZT0-3 5.414723333333333 3.90883 7.70948 ZT4-7 10.868970000000001 10.868970000000001 10.868970000000001 ZT8-11 23.345750000000002 23.345750000000002 23.345750000000002 ZT12-15 22.1728 18.668 25.677599999999998 ZT16-19 23.233249999999998 23.233249999999998 23.233249999999998 ZT20-23 8.947325 8.947325 8.947325