In August 2018 we reported that rail commuters in England's biggest cities were spending up to a fifth of their take-home pay on an annual season ticket.

Analysis by the BBC England Data Unit of more than 80 season tickets - based on a commuter using their ticket 228 days a year - covering journeys to London, Birmingham, Manchester, Leeds, Bristol and Liverpool, found:

• A full time worker on the median wage for one of these cities will spend an average of 11p in every £1 of their salary on an annual pass, after tax
• Commuters from St Albans, Sevenoaks and Harlow travelling to and from London 228 days a year can expect to pay more than 40p for every mile travelled
• Others travelling from East Didsbury and Macclesfield into Manchester and from Bath Spa into Bristol can expect to pay more than 32p per mile of their commute
• A season ticket from Southampton Central to London will cost £5,885, which is over a fifth of the average full-time take-home wage for London, £28,685
• Someone living in Cambridge and working in London will pay more than £5,000 for an annual pass, up from £4,952 in 2018
• Season tickets will have risen an average of 9% since 2016

The story involved working out the distances between stations and then taking that cost, the mileage and a 228-day working year. It also saw the first use of a dumbbell chart by the unit, produced in R by Dan Wainwright.

This is the fourth story the data unit has done on rail fare rises. 12 months ago, in August 2017, we published Rail fares: Commuters to pay £100 more in 2018. In January 2017, when price rises come into effect, we published Rail fares: Who are the season ticket winners and losers? and 2 years ago, in September 2016, we published Rail season tickets cost 10% of net pay.

The data in this story was based on the projections made at the time. The data predates the finalised increases that came into effect in January 2019 and may differ from the prices people pay from that date.

• CSV: RPI vs CPI rail fares

• Steve Chambers, Campaign for Better Transport (CBT)
• Paul Plummer, chief executive of the Rail Delivery Group

• Dumbbell chart (shown above): Rises in annual season ticket fares

You can see all fares-related stories under the 'fares' tag