condition mean min max ZT0-3 2.393886833333333 0.5925455 3.436045 ZT4-7 0.985767 0.985767 0.985767 ZT8-11 1.2623324999999999 1.2623324999999999 1.2623324999999999 ZT12-15 3.067085 2.96484 3.16933 ZT16-19 2.80058 2.80058 2.80058 ZT20-23 4.9269750000000005 4.9269750000000005 4.9269750000000005