Some colleges do post the results of their post-graduation surveys stratified by major (which is very important), but, even when they are available, they are not consistent across colleges. For example, some may report median pay level, while others report mean pay level, and the time frame of the survey relative to graduation date may vary. For example, here is WUStL’s own career survey results, where you can select a major to see outcomes for that major: Career Outcome Data - Students
https://collegescorecard.ed.gov/ can help you compare across schools the pay levels by major for recent graduates who received federal financial aid as students. However, small majors (commonly at small schools, or schools where few received federal financial aid) may have insufficient data to show results. For example, here is the entry for WUStL: College Scorecard | College Scorecard