condition mean min max ZT0-3 9.654765000000001 9.654765000000001 9.654765000000001 ZT4-7 6.71209 6.71209 6.71209 ZT8-11 8.369635 8.369635 8.369635 ZT12-15 11.2345 11.2345 11.2345 ZT16-19 15.630199999999999 15.630199999999999 15.630199999999999 ZT20-23 13.96865 13.96865 13.96865