Compute completeness for ESSD ms table(s)?

[bpbond]

On Twitter Carlos Guerra suggests

In your table 6 it would be nice to have the level of completeness of each ancillary variable (also if there is a geographic - e.g. biome - vias in reporting. Could be good for model evaluation. have u tried checking for spatial outliers or the possibility of regionalized models?

Could definitely compute completeness level for variables. Would it be useful?

#95