condition mean min max ZT0-3 16.8166 16.8166 16.8166 ZT4-7 14.722100000000001 14.722100000000001 14.722100000000001 ZT8-11 12.0515 12.0515 12.0515 ZT12-15 13.041599999999999 13.041599999999999 13.041599999999999 ZT16-19 17.08795 17.08795 17.08795 ZT20-23 14.99465 14.99465 14.99465