JACKSONVILLE, Fla. -- A new study shows an alarming trend that more women are being pulled over and arrested for driving under the influence.

"I think, no question, when it comes to traffic homicide, certainly you can see the trend as a percentage of the cases come in, a much higher percentage unfortunately now seems to be women defendants," Assistant State Attorney Mark Borello said.

The transportation department said the number of women arrested for driving under the influence has increase nearly 30 percent between 1998 and 2007, while the the number of men arrested under the influence fell 7.5 percent in the same period.

Just last year, Angela Harper was sentenced to nine years behind bars after she was convicted of DUI manslaughter on her own 13-year-old son.

Just a few months later, Lisa Green was also given a 10-year sentence after she plowed into a team of surveyors, killing a father of four.

But the study doesn't seem to explain why these numbers are going up.

"I'm a prosecutor, not a sociologist," Borello said. "So as you said, you can speculate on it, but clearly you've got more pressures on women now, more single women, single mothers who are probably driving more now, perhaps, than they may have in the past and drinking more, and that's obviously a deadly combination."

Despite the new trend, drunken driving arrests are still dominated by men.

But another pattern that seems to defy gender, according to Borello, is the type of impairments.

"We're seeing more drugs involved than we used to," Borello said. "The bulk of cases before were generally before with a BAC level and perhaps that would be it. Well, now you're seeing a combination of alcohol and drugs, a lot of prescription drugs."