env: es 6.2 + kibana 6.2

There are 5 hosts.Every 2 minute,the value of network bandwidth indexing to es by each host.For example：

host A.net_bandwidth: 200

host B.net_bandwidth: 400

...

The unit of measurement is "KB/s"

How can I visualize the total bandwidth of 5 hosts in time series? Approximate value is ok.

If i choose sum aggregation to do this, when the time interval greater than 2m,the result is far greater than actual value.

Thinks for your help.