Why Do We Use Present Perfect and Past Perfect to Talk about Charts?

CWould you please explain to me why I have to use PRESENT PERFECT or PAST PERFECT in the numbered examples?

"Could" is asking whether anyone has the ability to explain it to you while "would" politely asks people for their time to explain it to you.

CouldMay I just use past simple past instead of them?

"Could" denotes ability and is the past tense of "can." "May" denotes permission.

The chart refers to the pastdata from the years of 2000 andto 2009 and I have attached it below.

1. The given bar chart shows the data on the total number of new houses constructed from 2000 to 2009 in the neighboring cities of Derby and Nottingham.

Derby 1) HAS BUILT more new houses in the later years when compared with Nottingham.

Ah, I think I may have given this correction. Simple past works here, too.

While Derby built 45 new houses Nottingham 2) HAD BUILT 50 houses in the year 2000.

Simple past works here, too.

Nottingham's house construction 3) HAS FALLENfell sharply in 2006 and 2008 to fewer than 5 and 10 houses, respectively.

The sentence is incorrect since construction happened in the past. Here's an alternative sentence:

Nottingham's house construction 3) had fallen sharply in 2006 and 2008 to fewer than 5 and 10 houses, respectively.

2. In the year 2009 both Derby and Nottingham 4)HASD INCREASED its construction of houses to 345 and 250 respectively.

or

2. In the year 2009 both Derby and Nottingham 4) INCREASED its construction of houses to 345 and 250, respectively.

We always use a comma before "respectively."

3. Nottingham seems to have built more houses in 2000 with 50 houses and by 2007 the number of houses in construction increased to 190 compared to 120 houses in Derby.

This was a sharp rise from the previous year when fewer than 5 houses were constructed in Nottingham .

HIn 2008, howevver, in 2008 there were only 10 houses that were constructed in Nottingham while Derby had built 275 houses.

We avoid using "however" at the beginning of sentences in written English.

Finally in 2009 , the construction of houses in Nottingham increased to 250 andwhile Derby 5) HAD SURPASSED its neighbouring city to haveby builtding 345 houses.

"Neighboring" is the way we spell it in the US. Simple past works here, too.

Why Use Present Perfect and Past Perfect to Talk about Charts?

The chart refers to the past years of 2000 and -2009 and I have attached it below.

"2000 and 2009" makes it sound like you're only talking about those two years. Adding a date range ("2000-2009") or saying, "the time period between 2000 and 2009" or "2000 to 2009" or "The chart contains data from the year 2000 to the year 2009" make it clear that you're providing data for every year.

Derby 1) HAS BUILTbuilt more new houses in the later years when (than/compared with) Nottingham.

I'm not a grammar expert, so this might not be 100% accurate. This is just based on my intuition, and this grammar is a bit advanced so it's kind of hard to explain.

Since this chart's data is in the past, past perfect sounds better to me than present perfect for these examples. "has built" sounds a little weird to me because it sounds like construction (or the state of having constructed) is continuing past 2009 into the present day (2023). And example of "has built" would be, "Derby has built more new houses than Nottingham in recent years." This implies that Derby still builds more houses than Nottingham today.

"built" sounds better to me here because you're talking about what Derby did during that full time frame, not what state they were in. "had built" refers to being in the "state of construction being finished." "Derby had built more new houses in the later years than Nottingham(, but...)" sounds you're saying that, at that time, there were more houses built in Derby than Nottingham.

Instead of saying "built/has built," saying "the rate of building/construction" or "the number of houses built per year" could be used if you want to use past perfect. For example, these both sound good to me:
"Derby built more new houses in the later years."
"The number of houses built per year in Derby had exceeded Nottingham's by 2007."

While Derby built 45 new houses Nottingham 2) HAD BUILTbuilt 50 houses in the year 2000.

See above explanation.

Nottingham's house construction 3) HAS FALLENhad fallen/fell sharply in 2006 and 2008 to fewer than 5 and 10 houses respectively.

"had fallen" and "fell" feel interchangeable here because Nottingham was both in the state of having a lower construction rate and the construction rate completed the action of falling in these years.

2. In the year 2009 both Derby and Nottingham 4)HAS INCREASED itshad increased their construction of houses to 345 and 250 respectively.

3. Nottingham seems to have more houses in 2000 with 50 houses and by 2007 the number of houses in construction had increased to 190 compared to 120 houses in Derby.

"by 2007" gives a point in time, so using "had increased" feels more natural here. You could also say,
"and in 2007 the number of houses in construction increased to 190"

This was a sharp rise from previous years when fewer than 5 houses were constructed in Nottingham .

Howevver, in 2008 there were only 10 houses that were constructed in Nottingham while Derby haconstructed 275 houses.