Your logic is very strange. You did not accept the total period, now you complain about the short periods...
The fact is that in all these periods Maria is more popular than Rafa and Novak in US. And it is nothing new. it is a known fact for many years. All sponsors know it. That's why Sharapova has big contracts in US, but Rafa and Novak have not.
Popularity is not a constant number. It is a dynamic function of many parameters. Sportsmen have ups and downs, sometimes have injuries, and so on. And it reflects in their popularity. That's why the popularity is usually measured for the whole period of activity. And if we talk about the world then the advantage of Sharapova is even bigger. She is very popular in the big Asian countries where Rafa, Federer and Novak are not popular.
On the contrary in the Spanish speaking countries Rafa is by far the most popular.
Everything is very clear and very simple.
What are Sharapova's big U.S. contracts? I know she has a huge contract with Nike, but Nike is a global company so that hardly reflects that she is enormously popular in the U.S. She did have a commercial for Canon, but I haven't seen one of those commercials in a few years. I do see Kim Clijsters and Roger Federer commercials quite frequently though.
Regarding me having poor logic because I did not accept your "web searches over time" charts as proof that she is enormously popular. I didn't complain about the length of the periods. It doesn't matter how long the period you show is. The entire period showed nothing but a spike of popularity in 2004 when she won Wimbledon, and a spike in 2012 when she won the FO. The shorter time period showed the spike in 2012. She has spikes when she wins something. If she were truly as enormously popular as you think she is, she would not only have web searches when she wins something.
And, it is not true that "in all these periods Maria is more popular than Rafa and Novak in US." There are points when their lines are higher than hers, and if we accept web searches as an indicator of popularity, that means at those points in time, they are more popular. If you look at the past 2 or 3 years, you will see that Wozniacki got as many or more web searches in the U.S. as Maria did for a period of time. Would you use that to argue that Wozniacki is worshipped and loved in the U.S.? Probably not, so why do you use web searches to argue that Maria is worshipped and loved in the U.S.? I am not saying that she is not known at all. But, she is certainly not some huge tennis icon in the U.S., loved by even non-tennis fans.