Show Historical PSA/CGC POP Report

It would be extremely helpful if each trading-card page showed how its PSA/CGC population has changed over time, rather than only showing the current population by grade.

Ideally, the Population Report section would include a historical chart with:

• PSA 10 population over time
• PSA 9 population over time
• Total PSA/CGC population over time
• Population added during the last 30, 90, 180, and 365 days
• Percentage growth during those periods
• The dates of the population observations
• An option to select other grades
• Monthly or weekly history where available

A simple summary could show:

• Current PSA 10 population
• New PSA 10s during the last year
• Annual PSA 10 population growth
• Current gem rate
• Whether population growth is accelerating or slowing

Price history is much more useful when it can be compared with supply growth. For example, two cards may have similar prices, but one may have a stable PSA 10 population while the other is adding hundreds of new PSA 10s every month.

PriceCharting already has historic sales charts and current graded population information, so adding population history beside the price history would make the trading-card research pages substantially more useful for deciding whether a card is worth grading, buying, or holding.