Analytics show that users spend an average of four minutes looking at an article page on the website. A typical person could read around 900 words during this time. Aim to limit the amount of analysis on the page to be shorter than this.
We also know that users only read the first 25% of a page, with most only reading the Main points. Put your most important or interesting information first to make sure users see it; think of the inverted pyramid when writing your article.
If you need to write more than this, consider who you are writing for, and how much value they would get from this extra content. We know that even expert users value getting information from the ONS website quickly and clearly. Consider splitting your content into separate articles and linking between them. This will give your articles a clearer focus.