handle cases where the NUTS area is smaller than grid scale

[kimlee87]

This mean there is no gird point inside the NUTS area, hence no aggregated value.

How do we handle these case logicially and effectively?

Also, there are some NUTS3 regions inside another NUT3 region.

[kimlee87]

Updated: besides the "NUTSx inside NUTSy" relationship for a same NUTS name with x > y, there are no other cases like this, i.e. no NUTS3 inside another NUTS3.

However, we have 4 areas that do not have level 3: ['BA01', 'BA02', 'BA03', 'UA'] with level 2, 2, 2, and 0, respectively.