data rate different between quicktimes

looking for some verification here...

I've rendered two quicktimes in animation compression (at 16 bit), and have noticed that the data rate is vastly different between the two.

In Quicktime, when I pull up the Movie Info, the Data Rate for one is about 10 times larger than the other movie.

Both movies have small amounts of complexity, and for the most part are titles on a flat colored background.

The longer movie has the lower data rate, which is why I bring this up.

The longer movie also usually has a flat white background, while the shorter one has various flat colored backgrounds.

Can this explain the anomaly?

thanks.

Rich