Shalom,
   This is the hyperlink to the Nasa site for comet Tempel

http://deepimpact.jpl.nasa.gov/science/tempel1.html

It says that the comets orbit is a 5.75 year orbit around the sun.

The book by Schaaf...says that only 33 1/3 years does the comet appear with its Leonid  meteor  Shower.

That is how I came up with the two figures of about every 6 years do we see the comet, while every 33 1/3 years do we see it with its meteor shower.  My way of expressing these number of years may have confused everyone.  I appologize...

Shalom,
Miriam