Converting individual years to yearspans

Enclosed is the source code for an existing project. Please see below for details. ## Deliverables Enclosed is a database plus sample project. What is needed is to convert the individual years for the makes/models to yearspans (YearFrom to YearTo). Enclosed is an example of what should be the results of one part number. However; cannot just hard code it in. Has to first group the makes/models for each of the years; then any that increment by one will be part of one entry (as descibed in the sample enclosed). Must remain in VB.net Must work with the sample provided. What is needed is the function completed (where it currently says NotImplemented). Cannot create a new sample from scratch. The deliverables must work on the buyer's environment. Let me know if you have any questions.