California State Teachers Retirement System, Sacramento, reported a 13.35% return on its investments for the year ended June 30. CalSTRS assets as of that date totaled $99.9 billion, an $11.8 billion increase from June 30, 1998. This is the fifth straight year of double-digit returns for the pension fund. CalSTRS also outperformed 91% of public and corporate pension funds with more than $1 billion in assets, according to the Trust Universe Comparison Service, which measures relative performance of pension funds. The service reported that CalSTRS peer group had a median investment return of 10.8% for the year. The strong performance was driven primarily by high returns in the domestic and international stock markets. As of June 30, CalSTRS had 46% of its assets in domestic stocks, which returned 19.3% for the year; and 24% in international stocks, which returned 12.9%. CalSTRS investments in real estate, alternative investments and cash, which total 5% of the portfolio, also performed well, with returns of 21.2%, 16.4% and 5.9%, respectively.