Except as otherwise provided by a specific statute:
1. The amount of compensation and benefits and the person or persons entitled thereto must be determined as of the date of the accident or injury to the employee, and their rights thereto become fixed as of that date.
2. If the employee incurs a subsequent injury or disability that primarily arises from a previous accident or injury that arose out of and in the course of his or her employment, the date of the previous accident or injury must be used to determine the amount of compensation and benefits to which the claimant is entitled.