Not sure. My time officially being at TCU started in 1999 and I started following them and became a fan the year before in my final year in high school. They had a QB at the time who was a great athlete and runner but with passing at times, not so much (Patrick Batteaux) - he actually had a brief stint as a wide receiver with the Chargers for a few years. Also in 1999 and 2000 Tomlinson shined, so it could be a good bet it might have beeen around those years where we maybe just threw it around 10 times.
Boykin is still going to make mistakes being thrown into the fire so soon. We've seen him though throw for yards and make passes when the game situation allowed it - Texas Tech, parts of West Virginia, Baylor, etc. He's struggled through the air a bit more lately but with Texas's problems to stop the run game most of this season, along with the success of doing it those first two drives even though the last one didn't yield a score, made sense to just keep doing it. And Boykin played a solid role in that aspect.