Make it mandatory for children's social care to record the religion of children

I run an independent fostering service and have extensive experience recruiting and supporting Muslim foster carers and adopters. It isn't possible for me to get an accurate figure of how many Muslim children have been placed into non-Muslim adoptive and fostering homes. When I've submitted Freedom of Information requests, many providers say that they don't have the data or it would take them too long to collate the information. Without the data, I can't recruit effectively.