"In Italy," he added, "depending on the successes of Ferrari, the drop is 20 per cent based on data from the first five races of 2014."
A closer look at Italy is even more worrying. Considering only the Canadian grand prix, the combined losses by broadcasters Rai and Sky in just a single year was almost 3.5 million viewers.
"Spain, always with an eye on Fernando Alonso, is at a 15 per cent decline", said Sanz.
The analysis said the ratings decline began with Sebastian Vettel's utter dominance a few years ago, when the global audience fell from 515 million in 2011, to 500m in 2012.
And Bernie Ecclestone's FOM company revealed a further drop of 50 million viewers last year, ending with a nine-race winning streak by the Red Bull driver.
Sanz said major markets in China and France have not helped the situation, when the Chinese state broadcaster CCTV's coverage ended, while France moved to pay TV.
Germany's ratings decline was reportedly 10 per cent last year, but it has continued to drop a further 3 per cent in 2014, despite the prominence not only of Mercedes, but also the top form of championship leader Nico Rosberg.
If you ask former F1 team boss Flavio Briatore, the big problem in 2014 is the regulations.
"What we have now is not formula one. Formula one is something else," he told Italy's Radio24 after the Canadian grand prix.
"The audience is clearly enjoying it a lot less, because there are cars that do not make much noise.
"There are drivers who save fuel, drivers who only do 'fake' overtaking when their wing flap is open. Drivers who are doing their accounting in the car rather than being gladiators," Briatore charged.
F1 chief executive Ecclestone has also been highly critical of F1's new era, and particularly the quieter V6 engines.
But he is not overly worried about the TV numbers.
"I was talking to the people from RTL television in Germany," Ecclestone told Forbes last month.
"They said it is surprising that across everything they do, television ratings are down," he is quoted by F1 business journalist Christian Sylt.
"Why? Because people have only got so much time. They are using Facebook, Twitter ... there are so many things people can watch.
"You see the ratings have gone down but in the end they will go back to watching television," Ecclestone added.