Jo Stevens, MP for Cardiff Central, put this figure to the Prime Minister at Question Time yesterday (21 October 2015).

The fact-hounds at Full Fact, were on this like a shot (the screengrab above). Ms Stevens didn’t give a source but more often than not this is the Trussell Trust, the single biggest provider of food banks in the UK.

Percentages aren’t pretty at the best of times. Percentages above 100% even less so. They’re close to the top of the list of things people tell me they least like about statistics.

What does an increase of 1665% actually mean? It sounds enormous – after all it’s above a thousand.

Let’s have a look at how we get that number. First, note that the round numbers Full Fact gives aren’t the ones to use; we need the precise figures from the Trussell Trust. My source is this image:

In 2010-11, the number was 61,468. In 2014-15 it was 1,084,604.

The increase is (1,084,604 – 61,468) = 1,023,136.

The percentage increase is the difference divided by the starting figure multiplied by 100 …

(1,023,136 ÷ 61,468) x 100 = 1,664.5 to one decimal place

Or, in round numbers, the percentage increase is, indeed, 1,665%.

I’m feeling confused-ish and I work with percentages a lot!

Is there another way of saying this which is more easily understood?

The simplest is to say how much bigger the 2014-15 use (1,084,604) is compared to the 2010-11 use (61,468). That’s a simple division …

1,084,604 divided by 61,468 (or 1,084,604 ÷ 61,468)

which comes to 17.65 … the big number is about seventeen-and-a-half times the size of the small number. It’s not that far off eighteen (18) – but that might be over-egging the size of the number.

This feels a bit easier to understand but is there a way of making it even easier.

How about:

In 2010-11, people used Trussell Trust foodbanks a little over 61,000 times. In 2014-15, there were well over a million uses. In other words, for every one time a foodbank was used in 2010-11 there were more than 17 uses in 2014-15.

This isn’t necessarily the best expression but it does humanise the figures and, I hope, make them more relatable and understandable.

- This is the kind of thing I cover in my workshops – book yourself onto an open workshop, or get your organisation to do one in-house.

NB The wording is a bit tortured because not every use of a foodbank is by a unique individual; sometimes people have to go back a second or third time, and each one counts as a use.

Tip: when typing out figures such as 1,084,604 in a document type once, check (correct if necessary) and then cut-and-paste thereafter.

Each time you type it’s possible to make a mistake – most commonly switching two of the numbers (imagine if you typed 1,804,604 instead of 1,084,604 – would you spot it? Would someone unsympathetic to your view?).