condition mean min max ZT0-3 6.19709 5.413145 7.503575 ZT4-7 3.4950200000000002 3.4950200000000002 3.4950200000000002 ZT8-11 3.90681 3.90681 3.90681 ZT12-15 9.514885 7.660539999999999 11.36923 ZT16-19 11.69243 11.69243 11.69243 ZT20-23 10.95642 10.95642 10.95642