​ Scatter Plot

For 1940, using a chart I rendered with Excel, there should be around... 430? I think...

 

I just kinda traced the line to the place 10 years ago.

 

For 1997, my chart gives me an estimate of 1760 or so.

 

For 2005, i'd say around 2100

 

Feel free to ask if you don't understand anything!