condition mean min max ZT0-3 3.1430800000000003 3.1430800000000003 3.1430800000000003 ZT4-7 2.5851499999999996 2.5851499999999996 2.5851499999999996 ZT8-11 2.00714 2.00714 2.00714 ZT12-15 1.9990100000000002 1.9990100000000002 1.9990100000000002 ZT16-19 3.337475 3.337475 3.337475 ZT20-23 2.590025 2.590025 2.590025