Birth dates on WWI Draft Cards

A search of the World War I Draft Cards at Ancestry indicates that there are 10,893 draft cards for an individual born in 1918. When looking at these cards (I sampled 50 and quit) all of them did indicate a birth year of 1918 on the card, an obvious error. The indexers were told to transcribe the cards EXACTLY as they were written. We've posted a few of these cards here on our site:

http://www.rootdig.com/wwi/unusual.html

The database can be searched directly at Ancestry.com here
World War I Draft Registration Cards, 1917-1918.

Michael