Statistics don't predict the future, they present actual data of past incidences and factor in probability. Probability does not count on Festivus Miracles or the Spanish Inquisition...or dumb luck.
Things with more incidences have more probability, or another example would involve the potential damage that could happen if conditions were met.
Head injuries vs. torso or lower extremity injuries...the effects of blunt force...internal or external...speed, force and what you impact...
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I don't know nothing, and I memorized it in school and got this here paper I'm proud of to show it.