condition mean min max ZT0-3 17.186575 9.985675 21.1511 ZT4-7 10.028680000000001 10.028680000000001 10.028680000000001 ZT8-11 11.8279 11.8279 11.8279 ZT12-15 11.5765 11.51375 11.63925 ZT16-19 13.1831 13.1831 13.1831 ZT20-23 20.465 20.465 20.465