Over the past 3 years, a cloud service has been unavailable for a total of 36 hours, primarily due to a denial of service attacks.

Over the past 3 years, a cloud service has been unavailable for a total of 36 hours, primarily due to a denial of service attacks. Additionally, the physical server hosting the cloud service crashed once. It took the cloud provider 4 days to replace the physical server and for the cloud service to become operational again. Based on these statistics over the past 3 years, what is the availability rating of the cloud service?