500 or 200 year time average/mean in netcdf file

Hi, I have a nc file that contains time from 1 to 2000 and variables at global scale. How, I can average one variable with 500 years time at global scale. I want 500 years average so that I can use facet_wrap (ggplot) for plots at 500 years mean interval.

In simple, how to do average of variable at 500 year scale in netcdf file?

We'll need a reprex of your data to give any kind of detailed help. If you need help with a reprex, you can look at this post:

Closer - we still need a version of your data that we can put into our own R session. Try posting the output of dput(head(nc_data, 1000)).

I tried to add dput file here but it is showing 502 error. You can find nc file here-- https://zenodo.org/record/1198817/files/da_hydro_AprMar_r.1-2000_d.05-Jan-2018.nc?download=1