I have a singlestat panel that shows active connections to an nginx server. For both instances of what I am doing, I have the Calculation set to Current on the Visualization tab. If I toggle on Instant, I see the number of connections being 5000. If I toggle off instant and put on Spark Lines, I see the connections equal to 1. The spark line is at a peak, indicating to me that it is not 1. What is the different between Instant and Current when it comes to singlestat?