Sqlite - aggregating and concatenating by 2 identifiers

There's a particular SQLIte command I want to run to perform a aggregate and concatenate operation.

I need to aggregate by "ID" column, then for each ID, concatenate unique 'Attribute' and also concatenate average of 'Value' for each unique corresponding 'Attribute'

Please see attached table for explanation Example Table

I can do concatenate unqiue Attribute and aggregate by ID, but haven't got average of Value working.. thanks for any help!