I wouldn't guess any number, but as other witnesses have said, it's a minority, for sure. There's a lack of funding, in general, but it's probably even more pronounced for children's research. That goes from fundamental research all the way to clinical trials, which are also difficult to conduct for children. There's probably, also, underfunding for clinical trials in children's diseases or for children's medications that are in development.
I wouldn't want to guess any number, but it's probably even more severe than what we see for adult research.