Tom - welcome to the forum and good luck with the class. Please keep us posted on your prep and how it goes.
With respect to your question, there is a very easy answer. The book is 5 years old and the data (even for 1997) was updated since the book was printed. There isnt much detail, but you can see a note about it at the following forum page:
http://www.eiolca.net/forum/phpBB2/viewtopic.php?t=214
Anyway, I get the same results as you so you're not otherwise doing anything wrong - just using different data than when book was written.