Display actual RAM usage in percent

I want to display the actual usage of my RAM, the problem is that the stats that I got don´t fit, cause the pannel doesn´t update.
I´m a starter in Grafana thats why I´m asking the community right now.
The metrics are already on the host-server, so this is not the problem.

Maybe it is only a problem with the settings, but I tried a lot and didn´t find any solution.