lesbian teens more likely to get pregnant?!

From "Findings" in this month's issue of Harpers...

News of research from Canada on the likelihood of "lesbian" and "bi-sexual" girls getting pregnant-- as published by Saewyc in the Canadian Journal of Human Sexuality...

From an article by Amy O'Brian in the Vancouver Sun...

The data used for the research were gathered from adolescent health surveys done in B.C. schools in 1992, 1998, and 2003....

Results from the surveys, which were conducted anonymously among about 30,000 students in grades 7 through 12, indicated as well that boys are more likely to cause a pregnancy if they identify as gay or bisexual.

In the 1998 survey, 10.6% of girls who identified as bisexual reported pregnancy, and 7.3% of lesbians reported pregnancy. Among the heterosexual girls, 1.8% reported pregnancy.

What does this mean?