It’s been quite the run for Mulligan, who returns to this list after a three-year hiatus. Not only has the CEO increased the number of Guardian customers by 400% since 2012—from 5 million to 25 million—but she also managed to achieve record revenue of $12.9 billion in 2016 and expand to India and Canada over the past two years. Her influence is growing beyond the insurance world as well: She joined fellow CEOs in meetings with the White House to discuss infrastructure, workforce development, and tax reform.