condition mean min max ZT0-3 3.830448333333333 3.551815 4.246824999999999 ZT4-7 2.64564 2.64564 2.64564 ZT8-11 3.224615 3.224615 3.224615 ZT12-15 5.90175 4.843495000000001 6.960005 ZT16-19 4.641909999999999 4.641909999999999 4.641909999999999 ZT20-23 6.07654 6.07654 6.07654