you can use cross joins instead of blending.Joins are always better than blending.
Establish the relationship like this
You cannot blend the data sources with year because both data is from different years.
You can only blend with Country field and compare Economic values from both 2014 and 2015 years. I've created one sample take a look
Let us know if this help.
FSI_examples.twbx 141.0 KB