[FEATURE]: Elevator Outage metric

[kaushik12]

Is your feature request related to a problem? Please describe.
Current elevator outage metric only looks at uptime. There is a need for a better metric.

Describe the solution you'd like
Given the available data, we can look to quantify outages based on

• Number of commuters passing through respective stations
• Importance of an elevator in the accessible pathways within the station