A medical school wanted to know to what degree the college's existing curriculum prepared students to pass the national medical licensing exam. They obtained the exam scores for 38 students who had recently completed the curriculum. The following set of numbers represents a sample of the data: [150, 150, 162, 168, 171, 171, 182, 184, 188, 199, 199, 199, 220, 220, 228, 228, 232, 244, 253, 253] Use this sample to answer the following question: What is the frequency of the value 199?