How to compute meaningful Query Latency our users are experiencing (near real time)

We are running Elasticsearch 6.3 (Basic License). We gather Indices Stats data, specifially these fields:| |68,541,282|| |9,417,494|

I would like to compute Query latency data points throughout the day to gauge what our real-time users are experiencing. Questions:

  1. If I divide the search.query_time_in_millis over the search.query_total will that produce a meaningful Query Latency measurement that I can accurately depict user experience with search?

  2. Does the search.query_time_in_millis represent the total Query Latency, including the Waiting Time, or is this just the Service Time (as described here in this Presentation: @12:50)

Noone can help clarify those two data items? I've tried searching the documentation but no luck.