Guess the data: a travel statistics quiz
Most people think they can read a trend. This travel statistics quiz puts that instinct to the test: the chart below shows the start of a real, sourced data series — the reader draws where they think it went next, then reveals the truth and scores how close the guess landed.
Pick a dataset from the menu below — each one is the opening years of a real, sourced series, from the worldwide price of mobile data to the rate at which airlines mishandle luggage. The chart reveals the first few points; draw the rest of the way, then hit Reveal. The gap between the guess and reality is usually the surprising part.
According to Cable.co.uk's Worldwide Mobile Data Pricing study, the global average price of 1GB of mobile data fell steadily every year: from $8.18 in 2019 to $5.09 in 2020, $4.07 in 2021, $3.12 in 2022 and $2.61 in 2023 — a drop of roughly 68% in five years. The surprise for most readers is how long it kept falling rather than levelling off. It finally did: by the 2026 edition the global average had essentially flattened, at $2.59 per 1GB across 237 countries and territories. Source: Cable.co.uk, Worldwide Mobile Data Pricing (2019–2023 series; 2026 edition).
Diet Detective's annual study of US airline food found the average calories per menu item rose almost every year from 360 in 2012 to a peak of 405 in 2017, then reversed — falling to 373 (2018–19) and 375 (2019–20). Meal calories vary far more by airline than by year. Source: Diet Detective / Hunter College Airline Food Study, 2012–2020.
According to SITA's annual baggage reports, the global airline baggage mishandling rate fell from 18.88 mishandled bags per 1,000 passengers in 2007 to about 5.7 in 2018 — a drop of roughly 70% even as passenger numbers rose sharply. The fall was steepest early (18.9 in 2007 to 9.0 by 2011), then flattened, with small upticks in 2010, 2014 and 2018. Source: SITA Baggage Report / Baggage IT Insights, 2007–2018.
The steep early fall is the part that fools people. Between 2019 and 2020 the global average dropped by more than a third, from $8.18 to $5.09 per gigabyte, so a natural guess is that the decline either continued just as sharply or flattened out entirely. In reality it did neither: prices kept falling, but the pace eased year on year, landing at $2.61 per gigabyte in 2023 — and then, in the 2026 edition, essentially flattening at $2.59.
The driver is competition and network upgrades. As 4G and then 5G coverage spread and prepaid data bundles grew larger, the cost per gigabyte collapsed in the cheapest markets while wealthier markets lagged behind — which is why headline averages hide enormous country-to-country gaps. Travellers feeling that gap first-hand can compare connectivity options in the travel eSIM guide, or browse the full archive of sourced figures on the statistics page.
More draw-your-own-trend puzzles are collected in the data tools section, and every series links back to the reporting it came from. The TravelStatsMan Data Desk publishes only figures it can cite.
- Cable.co.uk — Worldwide Mobile Data Pricing (global average per 1GB: $8.18 in 2019, $5.09 in 2020, $4.07 in 2021, $3.12 in 2022, $2.61 in 2023, $2.59 in the 2026 edition; 237 countries and territories, 5,603 plans sampled).
Frequently asked questions
How does the guess-the-data quiz work?
The chart reveals the opening years of a real, sourced data series and then stops. The reader draws the line where they think it went next, hits Reveal, and the tool overlays the true series and scores how close the guess landed. The interesting part is usually the gap between the instinct and the reality.
Are the trends in the quiz based on real data?
Yes. Every series is a real, cited dataset, not an illustration. The mobile-data prices come from Cable.co.uk's Worldwide Mobile Data Pricing study, the baggage figures from SITA's annual baggage reports, and the airline-meal calories from the Diet Detective / Hunter College Airline Food Study. Each puzzle links back to the full report the figures came from.
Which datasets can be played?
Three at launch: the global average price of 1GB of mobile data (2019–2023), airline bags mishandled per 1,000 passengers (2007–2018), and average airline-meal calories (2012–2019). The dataset menu above the chart switches between them, and each keeps its own source and reveal point.
Does the quiz work on mobile and without JavaScript?
Drawing needs JavaScript, and the chart supports both mouse and touch input so it works on a phone. When scripts are unavailable, each puzzle falls back to a written summary of the full series and its source, so the underlying numbers are never locked behind the game.
How is the score calculated?
The score reflects how far the drawn line sits from the real one on average across the guessed years — the mean absolute error — with a separate check on whether the overall direction was right. A guess can catch the trend but still miss the size of the move, which is why the tool reports both.