attribute table - Color in QGIS based on record of events in CSV file?

I have a shapefile with the following attributes:

ID    Region
1     Region1
2     Region2
3     Region3

Also I have the following record of events in a CSV file

EventID     Year     Month     RegionID     Quantity
001         2015     12        1            6
002         2015     12        2            7
003         2015     12        3            3
004         2015     11        1            4
005         2015     11        3            3
006         2015     10        2            6
007         2014     12        3            3
008         2014     11        2            2
009         2014     10        1            7

...         ...      ...       ...          ...

I would like to color my map acording to a filtered record. For instance, say I want to display all the events of November 2015. Then I would have:

ID    Region    Quantity
1     Region1   4
2     Region2   0
3     Region3   3

Or say I would like to display all the events of 2015. Then I would have the sum of the events:

ID    Region    Quantity

1     Region1   10
2     Region2   13
3     Region3   6

Is there a way to solve this problem dynamically, without rewriting the attribute table of the shp every time?

Consider that the CSV file is updated frequently.