Ratio of RU to DU to CU in current deployments

I am curious about the breakdown of RAN components and their deployments. I am unable to find the ratios of RUs to DUs for a commercial deployment. I just want to know generic estimates which are good to use for practical purposes.

I see that some places mention the ratio to be 1 DU for 1 RU while some places mention the ratio to be 1 DU for ~10 RUs and some mention 1 DU for ~100 RUs.

Can someone share more information on which of these is more practical? And in which scenario?