How to interpret correctly this chart about nitrogen oxide?

Question

I found the below chart in a test for university access in Sweden, with the following question:

How large was the total emission of nitrogen oxides caused by Swedish consumption under the period 2004-2008?

I have the correct solution, but it does not match my answer. I reasoned like this:

• Both 2004 and 2008 should be included, so we have 5 years.
• The emissions abroad are about 112 thousand tons on average, so 112*5 = 560
• The emissions in Sweden are about 225 thousand tons on average, so 225*5 = 1100.
• So the total should be about 160+1100 = 1660.

However, apparently the correct answer is 1100.

I am quite sure I am missing something obvious, but I cannot figure it out.

Translation of the most important terms:

Utsläpp i Sverige: emission in Sweden
Utsläpp utomlands: emission abroad (caused by imports).

The original question in Swedish:

Hur stort var det sammanlagda utsläppet av kväveoxider orsakat av svensk konsumtion under perioden 2004-2008?

Answer 1

A person answered to me on a dedicated Facebook group. He suggests that the labels are about areas, not lines, so the grey area (emissions in Sweden), is only the visible area, it does not continue below the dark area (emissions abroad). I find this representation very confusing.

As an example, the emissions in Sweden in 2008 are 225 - 100 = 125, the difference between the total and the dark area, and not 100 as I thought.

This way, the correct answer is 1100, because the upper line already represents the total emissions, and between 2004 and 2008 we have an average of 225 for 5 years.