Overwrite date metadata 1970s ->

[ninpnin]

Riksdagen has (presumably) accurate date information in the JSON files from the 1970s onwards. We should overwrite the scraped dates from 1970 onwards. While I am relatively certain this will improve the quality of the date metadata, doing the sample check properly will ensure that.

Sidenote: Between 1970 and 1990, most of the records only cover one day, but these records are concatenated into a longer document, which is the one that has been scanned. As a result, each record PDF includes the table of contents for multiple records in the beginning, making annotation slightly more difficult.