Condition not passing into if statement

I'm trying to increase the count each time the function is run, it seems as though count is being reset each time the function is run. I think the count in the if statement may not be the same one that's passed as a condition. Thanks

def check_solution(user_solution, solution, count):

if user_solution == solution:
        count =+1
        print(count)
        return count
else:
    print("Incorrect")