eva and bruce are a young couple in good health. eva begins her new job as a dolphin trainer and is offered elective health care coverage from her company for a price less expensive than she and bruce would pay if they purchased insurance on their own. the policy provides the same coverage to all participants regardless of age or health status. every year for the next five years, they see an increase in their insurance costs. after five years, they receive a notice in the mail informing them that their insurance company has gone bankrupt. eva contacts the company to inquire the reasoning behind the company's failure. she is informed that over the past several years, healthier individuals chose to leave their insurance policy, shrinking the company's participant pool. eventually, no more healthy people remained in the pool except eva and bruce. the insurance company had no choice but to increase costs for all members. finally, they could no longer afford to operate. which term best describes what eva and bruce's insurance company has experienced?