in which drinkers tape a stack of their empty beer cans to the can from which they are currently drinking. The name comes from the fact that when the stack gets tall enough, it resembles a wizard's staff. United States Despite having a legal drinking age of 21, binge drinking in the United States remains very prevalent among high school and college students. Using the popular 5/4 definition of "binge drinking", one study found that, in 1999, 44% of American college students (51% male, 40% female) engaged in this practice at least once in the past two weeks. One can also look at the prevalence of "extreme drinking" as well. A more recent study of US first-semester college freshmen in 2003 found that, while 41% of males and 34% of females "binged" (using the 5/4 threshold) at least once in the past two weeks, 20% of males and 8% of females drank 10/8 or more drinks (double the 5/4 threshold) at least once in the same period, and 8% of males and 2% of females drank at least 15/12 drinks (triple the threshold). A main concern of binge drinking on college campuses is how the negative consequences of binge drinking affect the students. A study done by the Harvard School of Public Health reported that students who engage in binge drinking experience numerous problems such as: missing class, engaging in unplanned or unsafe sexual activity, being victims of sexual assault, unintentional injuries, and physical ailments. In 2008 the U.S Surgeon General estimated that around 5,000 Americans aged under 21 die each year from alcohol-related injuries involving underage drinking. Rates of binge drinking in women have been increasing; high risk drinking puts these women at increased risk of the negative long-term effects of alcohol consumption. The population of people who binge drink mainly comprises young adults aged 18–29, although it is by no means rare among older adults. For example, in 2007 (using a 5-drinks definition per occasion for both genders), 42% of 18- to 25-year-olds "binged" at least once a month, while 20% of 16–17-year-olds and 19% of those over age 35 did so. The peak age is 21. Prevalence varies widely by region, with the highest rates being in the North Central states. Binge drinking is more common in men than it is in women. The annual "Monitoring the Future" survey found that, in 2007, 10% of 8th graders,