The minimum number, or percentage, of ID numbers or names that are actually selected annually is also specified by the DOT. Non-regulated companies tend to use the DOT regulations as guidelines. Employees can consult their company policy or program administrator to find out what the percentage of random selection is for their company, although many companies treat this as confidential information. It may also be helpful to know that if a company with 100 employees decides to test at 50 percent ‘random rate’ it does not mean it will test 50% of its employees. Rather it will conduct 50 tests on whichever employees are chosen by the random selection computer program. It is not uncommon for the same donors to be selected several times in succession since all employees are available for each selection.