What I Don't Ever Get When I Buy a Kellogg's Card Lot

I haven't been buying any sizable lots of Kellogg's cards recently.  They just haven't been available as frequently.  When I have purchased these lots a few things are always missing.

1.  Nice 1971 cards.  No surprise with this.

2.  Nice 1975 cards.  No surprise here either.

3.  Nice George Brett cards including unopened cards.  Why is that an issue?  I've gotten unopened cards of Nolan Ryan and nice cards of Rose, Jackson and others.  What is everyone doing with the George Brett cards?

This lot was an exception since it only contained Brett cards.  I just don't find them from the earlier years.