# Classify area by year

I'm trying to classify a set of buildings (grey) in a layer, according to construction year, in a number of different areas (orange).

In Orange – areas with a sum of buildings inside.

The construction year information is inside the area’s layer… Ok, so I think this is a problem with data display, because all my data is organized like this:

So for Area D, there are 18 buildings built in 1940, and so on…

How can I classify this information to calculate maximum and show inside of each area what the most represented year is?

• u want a calculation or a "graphic" display ? Why not colouring the buildings according to the construction year ? – snaileater Jun 2 '17 at 18:15
• If you're up for some SQL Spatial, you can do this using shapefiles (i'm assuming you're using) with the QGIS DB Manager... – DPSSpatial Jun 2 '17 at 18:23
• classify each building by its year and have a unique symbology (color) for each year (if there isn't a large amount of unique years) – NULL.Dude Jun 2 '17 at 18:28
• What software are you using? Are you referring to using multiple attributes as the symbology? If so this can be done in ArcMap products under the layer's properties --> symbology --> multiple attributes. – Aggs Jul 25 '17 at 1:27

Enter this equation in the cell `F3` and copy it through.
``````F3: =INDEX(\$B\$2:\$E\$6, 1, MATCH(MAX(B3:E3), B3:E3, 0))
After getting `Year` (column F) filled, join the sheet with your area layer.