Can studying philosophy help one to become more creative? What percent of the
Yes. And 100%.
OK, perhaps those answers are too short and uncreative.
But yes, I think reading philosophy, thinking about philosophical questions, and trying to come up with and write about philosophical issues can stimulate creative thinking and improve one's creativity (perhaps not artistic creativity but new ways of thinking about things, new ideas, etc.). I think philosophy students tend to become better at imagining different options and solutions and at writing new types of arguments. I'm allowing my current senior major students to do a creative project to engage with the topic we're discussing (death and the meaning of life), and we'll see what they come up with, but music, drama/dialogues, short films, and video games are possibilities.
And it's 100% because original thoughts happen all the time. Each one of us experiences things in ways no one else has. If you meant original answers to philosophical questions, well, then it's probably much lower, but those are not so easy to come up with.