condition mean min max ZT0-3 9.4409 9.4409 9.4409 ZT4-7 8.2878465 8.2878465 8.2878465 ZT8-11 7.287867 7.287867 7.287867 ZT12-15 8.1913445 8.1913445 8.1913445 ZT16-19 9.5531985 9.5531985 9.5531985 ZT20-23 8.462418 8.462418 8.462418