condition mean min max ZT0-3 11.35 11.35 11.35 ZT4-7 13.6 13.6 13.6 ZT8-11 7.199999999999999 7.199999999999999 7.199999999999999 ZT12-15 15.35 15.35 15.35 ZT16-19 12.149999999999999 12.149999999999999 12.149999999999999 ZT20-23 16.85 16.85 16.85