Compared with patients who avoided these painkillers, those who took an NSAID had a 2.4-fold higher risk of a major bleed and those who took aspirin had a 1.5-fold higher risk. Even though [this warning about major bleeds with NSAIDS or aspirin] is on the warfarin label. . .
5 years. A decade means 10 years, so to find out how many years are  in half of a decade you would simply divide 10 by 2, which is 5.
century(Noun) A period of 100 consecutive years; often specifically a numbered period with conventional start and end dates, e.g., the twentieth century, which stretches from (strictly) 1901 through 2000, or (informally) 1900 through 1999. The first century AD was from 1 to 100.