/usr/share/eccodes/definitions/metar/runwayStateExtentOfContamination.table is in libeccodes-data 2.6.0-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | 1|Less than 10% of runway covered
2|11% to 25% of runway covered
5|25% to 50% of runway covered
9|51% to 100% of runway covered
/|Missing or not reported
|