Im undertaking a project that requires predicting the future direction of the semantic web.

One part of the project is to analyse how many applications were using RDF when it was originally set out, and to analyse how many applications NOW use RDF in order to predict a growth pattern in the next few years.

Where (if any) can i find data on the number of applications that use or have used RDF?

Any help appreciated, or directions to be pointed in.

Chris.