The California State Teachers' Retirement System or CalSTRS, reported a 12.3 percent return for the year ended June 30, quite a turnaround from a 25 percent loss in its portfolio for 2009. On average, CalSTRS needs an 8 percent return to meets it obligations, so it would appear to be ahead of the game. The bad news is that one good year doesn't make up for several weak years - and if the total pension assets are under 80 percent (that's the absolute minimum), taxpayers could be forced to pony up the difference.