How much thread does a bobbin hold??

I fill 3 types of bobbins and one spool to compare how much thread these bobbins will hold. Bobbins are for Singer 226, 201, 99, 66,221, 222K, 27, 28, 127, 128, others and for a National Two-Spool sewing machine. National made claims that it's two spool machine spool bobbins could hold up to 200 yards of thread back in early 1900's newspaper ads.