The survey was 4 questions. The first 2 questions were marketing - Which mostly prompted you to try the Stetzerizer filters? and How did you first hear about Stetzerizer filters? The last 2 questions are the important ones:
How did you install Stetzerizer filters? (According to recommendations - in every room throughout the house | Installed filters most areas in the house | Installed just a few filters in 1-3 areas | I tried only 1 Stetzerizer filter)
The final question and results you can see above. We have the raw survey results/responses, but I do not personally (nor anyone else employed by me) have the ability to analyze them to see if there is any correlation between the response in question 3 and the response in question 4. I would be happy to send the raw results to anyone who would like to look at this. I would suspect that those who installed them as recommended or installed more of them in more locations had better results. But the data needs to be analyzed to confirm that.