you should download the complete zip file which has them in png format and is clearer. If you want them to print in 8.5 x 11 Simply open them in “windows photo viewer”. Select paper size as 8.5 x 11 then print. you should select 11" x 17" for the national production chart.
converting to jpeg is a bad idea as it will blur the image. Just about any photo editing program can convert them to jpeg. the easist (not necessarly the best) method would be to open the files in paint then click “file” , “save as” then click the drop down menu and select Jpeg. click “save”
P.S. converting to bitmap is better since you wont lose quality.