In a Finnish study of morbidity and mortality from myocardial infarction a comparison was made of married and single men. The following results were obtained:

Myocardial infarction in men 40-64 years (age standardized rates)
  Incidence/100 000 person-years Mortality/100 000 person-years
Married 1 371 498
Single 1 228 683

What is the relative risk of myocardial infarction for married compared with single men?