I want to measure the throughput of read operations in Mongo. By throughput I mean "how many reads the system process in a given amount of time (every second)".

I run `mongotop 1` and I get:

```
                 ns       total    read    write    2018-05-21T08:01:25Z

 sampledb.samplecol        57ms    25ms     32ms        

local.replset.minvalid     28ms     0ms     28ms  

     local.oplog.rs         9ms     9ms      0ms 

admin.system.indexes        0ms     0ms      0ms  

admin.system.namespaces     0ms     0ms      0ms  

 admin.system.roles         0ms     0ms      0ms   

 admin.system.users         0ms     0ms      0ms    

admin.system.version        0ms     0ms      0ms   

           local.me         0ms     0ms      0ms   

  local.startup_log         0ms     0ms      0ms          

```

Is this means that the throughput of read operations is 25ms?