I just got done sorting through three five gallon bucket of wheel weights that I had picked up in the last 8 to 10 months at a well known tire dealer. The buckets were not got at the same time and I found it interesting to find that the newest bucket had about 25% steel wheel weights and the oldest was only about 5%. There were some zinc mixed in but not a great deal.
The reason I was sorting the weights was I was concerned that there might be a lot of Zinc but was pleased to find that was not the case.
Skeet1