In a corporate environment, the security team is analyzing the dashboard of the Cisco FireAMP for Endpoints to assess the effectiveness of their endpoint protection strategy. They notice that the dashboard displays various metrics, including the number of detected threats, the types of threats, and the response times to those threats. If the team observes that the average response time to critical threats is 15 minutes, while the average response time to high threats is 30 minutes, and they aim to reduce the average response time to critical threats by 50% over the next quarter, what should be their target average response time for critical threats?