The Regulator of Social Housing produces quarterly surveys setting out information such as the amount of borrowing registered providers have taken and where they got it from, the number of affordable home ownership homes they have built and sold, and the number of market sale homes they have built and sold.
Here is the latest survey:
Quarterly_Survey_for_Q4_2019-20
Here are the previous surveys:
https://www.gov.uk/government/collections/quarterly-survey-of-private-registered-providers