Pоlаris Cоrpоrаtion wаnts to offer an employer-sponsored group health insurance program for its employees - that will be financed by Aetna Insurance. Polaris Corporation has 12,500 employees in total. 10,000 of the employees are eligible to participate in the health insurance plan; and 9,000 decide to enroll in the plan once it is offered. What is the participation rate of the heath insurance plan?