The Alan Guttmacher Institute of sexually active men aged 20–39 found that 2.3% had experienced same-sex sexual activity in the last ten years, and 1.1% reported exclusive homosexual contact during that time.
Clinical studies by the Guttmacher Institute found that periodic abstinence resulted in a 25.3 percent failure under typical conditions, though it did not differentiate between symptom-based and calendar-based methods.
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