condition mean min max ZT0-3 16.50495 16.50495 16.50495 ZT4-7 9.76756 9.76756 9.76756 ZT8-11 8.586034999999999 8.586034999999999 8.586034999999999 ZT12-15 19.950499999999998 19.950499999999998 19.950499999999998 ZT16-19 32.58605 32.58605 32.58605 ZT20-23 22.1377 22.1377 22.1377