Yeah, so google it
Whiners annoy me.
The pdf is <a href="http://www.mathematica-mpr.com/publications/PDFs/impactabstinence.pdf">here</a>.
Your missing 56% is those who remained abstinent.
The statistical significance tests were performed, and the point is that the null hypothesis, that the two groups were drawn from the same distribution, could not be rejected. The associated p-values ranged from .32 (ReCapturing the Vision) to .90 (My Choice, My Future!) in total abstinence, and .28 to .79 (same) in abstinence in the last 12 months. The in-betweener programs studied were FUPTP and Teens in Control.
There were some differences: the overall identification of STDs in the program group was statistically significantly higher in the program group than in the control group, with p < 0.01.
Finally, on age, the report says:
"For both the program and control group youth, the reported mean age at first intercourse was identical, 14.9 years. This age is seemingly young, but recall that the outcome is defined only for youth who reported having had sex and the average age of the evaluation sample was less than 17." (page 18).