In Azure Advisor documentation (https://docs.microsoft.com/en-us/azure/advisor/advisor-cost-recommendations#optimize-virtual-machine-spend-by-resizing-or-shutting-down-underutilized-instances) it is mentioned that the current load should not go above 80% to recommend resizing to smaller SKU. What does this 80% utilization refer to (i.e. CPU Max/CPU avg over 7 days, etc.) ?