The intervention led to a small change in bike helmet use and a slightly larger change in seat belt use, but it did not lead to changes in alcohol variables or weapon carrying.
The intervention led to no changes in bike helmet use. 
mnli hypothesis: The intervention led to no changes in bike helmet use.  premise: The intervention led to a small change in bike helmet use and a slightly larger change in seat belt use, but it did not lead to changes in alcohol variables or weapon carrying.