The 3% figure comes from the chart below, which is measuring total number of services delivered to actual clients.
As this
Christianity Today article notes, clients can receive multiple services. Measuring by total clients, the abortion figure rises to around 10%.
Measuring by revenue produces a similar number:
Thirty-seven percent of Planned Parenthood's revenue comes from its health centers; potentially one-third of this health center revenue comes from abortion. Planned Parenthood does not list revenue from specific procedures, but pro-life activists estimate that around 10 percent of the organization's revenue comes from abortion. In other words, pro-life groups' best guess is that around one-third of one-third of the revenue comes from abortion.
So if you want to say that abortions represent 10% of PP's business, I wouldn't argue. That's a rational, defensible argument.
90% is a lie. "Most" is a lie.