Why doesn't the writer use past particle tense ?

[duiter]

Dear teachers,

Why doesn't the writer use past particle tense after by 2010 ?

A steady but significant rise can be seen in the percentage of the population that owned
a computer over the period. Just over half the population owned computers in 2002,
whereas by 2010 three out of four people had a home computer.

Why not ....... bby 2010 three out of four people had had a home computer instead of had

http://takeielts.britishcouncil.org/...el_Answers.pdf
Thanks

[konungursvia]

English is often unclear about past imperfect tenses being clearly expressed as imperfect, but here we use "had a computer" as a past continuous (imperfect) because people keep their computer for 2 years or more. If we chose a verb whose meaning conveyed an act that was punctual, inchoative, temporary or quick (e.g. to buy a computer) then we would use the pluperfect as you suggest ("had bought a computer").

Do you see my meaning?

[duiter]

Thanks for your reply

I am sorry, no I am still confused

[Raymott]

Thanks for your reply

I am sorry, no I am still confused

There's no need for the past perfect there (if that's what you mean by "past particle tense").
Can you explain why you think it should be "had had"?

[whitemoon]

I think he is confused with this sentence.(from the article he refers to)
In 2002, only around 15% of those who did not finish high school had a computer but this figure had trebled by 2010.
Just over half the population owned computers in 2002, whereas by 2010 three out of four people had a home computer.
Both are correct. The first sentence has the subject “this figure” and the second one, “three out of four people”. The subjects differ and so do the tenses: “had trebled” and “had”, although the time phrase is the same, “by 2010”.
Hope you understand!

[Tdol]

By 2010 three out of four people had a computer- they still had a computer
By 2010 three out of four people had had a computer- they may have stopped owning one

[MartinEnglish]

It would be weird to use the Past Perfect with a possessive have except to express for how long.
It 2008 I had a car.
In 2008 I had had my car for 6 years.

In your sentence 2010 is finished - so we just use the Past Simple. Is that clear now? Why do you think you'd need the Past Perfect?