@Aliarch ,
It’s not really clear what we are looking at in your results. All I can say is that a point-in-time illuminance simulation of electric lighting is accurate and trustworthy as long as you set it up correctly. Maybe you should upload your .gh file with the .ies file so people can see specifically what you are asking.
There’s no good way to simulate Luminare’s in Radiance for an entire year without running a separate point-in-time illuminance simulation for each hour. I would recommend trying to run illuminance simulations of “typical days” to get a sense of illuminance conditions with your .ies file and various solar positions.