Knight Frank just published their 1Q 2015 Prime Global Rental Index . We provide the U.S. info. Always a fascinating read.
In Moscow, prime rents have historically been US Dollar denominated but the weakness of the Rouble against the US Dollar has led an increasing number of landlords to swap their rents into Roubles. In US Dollar terms prime rents fell 42% on an annual basis but by only 5% in Rouble terms.
Here are the world rankings: