Using GraphQL via GitLab to discover the first commit of a file in a repository

I am using GraphQL to access the contents of a .repository hosted in GitLab. I need specific information about the files in a repository. Specifically when it was last modified and when it was created.

Using GraphQL to get the last commit information about a file is fairly straight forward:

query($projectPath: ID!, $filePath :String){
project(Path: $projectPath) {
> repository {
> tree(path: $filePath) {
> lastCommit {
> author {
> name
> }
> committerEmail
> committedDate
> }
> }
> }
}
}
{"fullPath":"my/path", "filePath": "myfile.txt"}

What I need is the first commit of a file, so that I can return the creation date of the file. So far, the Graphql schema in GitLab doesn’t seem to cover this.

Any suggestions would be most welcome.