@NewtronStar
Not very scientific really.
The means to acquire the call data has evolved over all that time and the spread of the data has increased as well.
You are getting calls because your data is being consolidated and harvested from anywhere & everywhere your data goes.
You may protect your privacy and information personally, but who controls the data once it is in someone else's computers.
It is easy to blame the foreign call centres as a source & recipient of the data but it could just as well be data that is sitting on a websites computers that has been harvested.
For every hack/crack and phishing event that is reported I am sure there are many more that are kept quiet or even worse have not been found yet!!
I receive scam emails and dodgy invitations that I suspect are simply my information has been 'hoovered up' from other people.
I do not frequent dodgy sites and therefore have not been hacked or had my local data accessed by them, they have simply built or acquired the lists from other sources.
It is the same as receiving mail for old addresses years after you have lived there.
This also happens every so often as the mail address lists are passed around.
(I have old neighbours who forward on mail at random times)
All this is a smoke screen to the real problem which is the Telcos do not want to engage in a war to solve this problem.
As they see it's an obstruction to business which costs them money to wage the war and to weather the impact on business.
If it was impacting their 'Bottom line' the fix would appear tomorrow, by pure happen-stance, I am sure.
Go figure !!