Promising a steady increse in FII investment limit in Government bonds, RBI Governor Raghuram Rajan on Thursday said the ceiling will be revised twice a year and efforts are being made to make such investment easier.Currently, the investment limit for government securities (G-secs) by Foreign Institutional Investors (FIIs) is $30 billion annually. Out of the $30 billion, FIIs are allowed to invest $25 billion, whereas $5 billion is for long-term investors.