condition mean min max ZT0-3 3.177415 3.177415 3.177415 ZT4-7 2.896785 2.896785 2.896785 ZT8-11 2.898365 2.898365 2.898365 ZT12-15 1.352065 1.352065 1.352065 ZT16-19 1.9407799999999997 1.9407799999999997 1.9407799999999997 ZT20-23 2.638605 2.638605 2.638605