Australia was the first country to make wearing bicycle helmets mandatory. The majority of early statistical data regarding the effectiveness of bicycle helmets originated from Australia.[1] Their efficacy is still a matter of debate.
^McDermott, F. T. (1992). "Helmet efficacy in the prevention of bicyclist head injuries: Royal australasian college of surgeons initiatives in the introduction of compulsory safety helmet wearing in Victoria, Australia". World Journal of Surgery. 16 (3): 379–383. doi:10.1007/BF02104435. PMID1589969.