Create a bus matrix based on the following information:

Imagine that you are a senior data warehouse architect for LECAL Corporation.  Your company has been contracted by the U.S. Department of Education to develop a data warehouse which will track student performance on a series of planned nationwide tests as part of a new STEM (Science, Technology, Engineering, and Math) initiative.

Specifically, new tests will be created for the five subjects of: algebra, geometry, calculus, chemistry, and physics.

The data warehouse to be designed will produce annual average test scores for graduating seniors for each test in the five subject areas.  All graduating seniors, regardless of the type of K-12 school they attended (e.g., public, private, parochial, home schooled, etc.), are to be included in the data warehouse.

The system must include all relevant courses in the students' course history and the final course grades.  Prerequisite courses and grades are to be included as well.  Course names and numbers are non-standard among the nation's school districts and educational institutions and tend to change from year-to-year.  Also, course grades are non-standard.