condition mean min max ZT0-3 16.54405 16.54405 16.54405 ZT4-7 12.59035 12.59035 12.59035 ZT8-11 15.67545 15.67545 15.67545 ZT12-15 16.18935 16.18935 16.18935 ZT16-19 20.049500000000002 20.049500000000002 20.049500000000002 ZT20-23 18.3701 18.3701 18.3701