I don't know if this sort of data is available, but I don't know how much shoulder pads necessarily help in that sort of situation. Growing up a kid a few years older than me got hit in the chest with a puck while wearing shoulders pads and his heart stopped and he died (I will caveat that this was in the '90s and shoulder pads have improved). As I understand, incidents of heart stoppage due to a puck to chest are incredibly rare. Sure, you can take the, "if it can save one life" sort of attitude. But at the same time you might as well wear your helmet while driving to rink as I would guess that is more likely to save your life than shoulder pads preventing heart stoppage from a puck to the chest, particularly if your car is older and doesn't have side airbags.
Edit:
I did some brief research and found this article: https://www.chicagotribune.com/investigations/ct-chest-protectors-commotio-cordis-standard-met-20160408-story.html. It focused on baseball mostly and summarized that there is no indication that chest protectors or even special heart protective gear reduce the risk of commotio cordis (apparently what it is called). The articles claims about 10-20 cases in the US, mostly younger boys, and is rare in adults. And the best solution seems to be immediate access to an external defibrillator to restore proper heart rhythm.