[superfad]

Cryptome was keeping a tally of what has been released. The problem is the total size of the trove is not known publicly. But yes, it would be a very tiny percentage.

https://cryptome.org/2013/11/snowden-tally.htm

[mirimir]

Thanks. That accounting has been updated through 18 November 2016. It seems like at most 1% has been released.