df output on systemd - /run/user/*

I have been using df -lh -x nfs --total to get the total disk available (with file-systems) and it has served me well, so far. With systemd, I see that there are entries in df for each logged in user:

$ df -lh -x nfs --total
Filesystem               Size  Used Avail Use% Mounted on
udev                     3.7G     0  3.7G   0% /dev
tmpfs                    758M   11M  748M   2% /run
/dev/mapper/system-root   78G  8.6G   65G  12% /
tmpfs                    3.8G  4.0K  3.8G   1% /dev/shm
tmpfs                    5.0M     0  5.0M   0% /run/lock
tmpfs                    3.8G     0  3.8G   0% /sys/fs/cgroup
tmpfs                     16M     0   16M   0% /mnt/my_ramdisk
tmpfs                    758M     0  758M   0% /run/user/1003     <<<<
tmpfs                    758M     0  758M   0% /run/user/1001     <<<<
total                     91G  8.6G   79G  10% -             

So, the total is off!

Should I just exclude the tmpfs with -x tmpfs or is there any better way to only exclude the systemd generated mounts ?

Thanks.