How can I see which processes upload/download how much data? [Debian 9]

So I'd like to gain some insight into which processes (incl. daemons) upload and download how much data on my Debian 9 machine. Sadly the System Monitor does not display such information. I'd prefer a GUI over the console. I have tried nethogs which is probably what people would recommend for such endeavors, however it only shows the *current* network traffic processes instead of cumulative information such as a proper statistic or ordered list. I'm aware of wireshark.