Overnight index swap

The sleight of compounding can also provide a very misleading picture about the slope of the OIS yield curve. If on October 2, the 6-month OIS closed at 5.75/5.80, seen against the 1-year quote of 5.80/5.85, the OIS yield curve appears to be slightly upward sloping. In fact, the average 6-month MIBOR implied by a 6-month OIS rate of 5.75 percent is actually 5.65 percent, slightly above the 5.64 percent implied by the 1-year market. This implies that the market is fact imputing in a lower average MIBOR rate in the latter half of the year, the hallmark of a downward sloping yield curve.

when i was reading one article on overnight index swap at that time i was confused on this paragraph, here underline shows my confusion point.
In this paragraph i got 5.64 % but i didn't understand how the article's author got 5.65 % and please clarify why is it downword ?