The Reserve Bank bought A$21 billion of government bonds between March 20 and March 27 and had a material impact on yields, according to analysis of the quantitative easing program the central bank announced in March 19.Fixed income market researcher BondAdviser said the RBA transactions had an average term of 4.8 years and an average yield of 58 basis points. Included in the transactions were $2 billion of state government bonds.Three-year Australian government bonds are now priced on a yield of 25 bps, which is the target the RBA set. The yield is down from a recent high of 55 bps on March 13.Three-year NSW Treasury Corp bonds fell from 1.02 per cent to 63 bps over the same period.