They also ended the giving ILE to a foreign national who had been married to a British Citizen for at least 3 years outside the UK. Changed to stop these people claiming welfare from the UK as soon as they arrived, when they had never contributed to the UK.
Some of the other changes already brought in, including the more recent changes, have started from a certain date. e.g. the dependant visa for the spouse of someone on a work visa. They brought in a limit to the number for absences for these, which means their 5 years to ILR clock starts again if they go over the limit. That rule started on a certain date, meaning those who had to renew their visa were under the new absence rules for that second visa, but on the old rules for their first visa.
A forty hour week, just being paid the hourly national minimum wage of £10.42 per hour, is £21,673 per year for just one person. That minimum income requirement can be earned between both in that couple, to renew a visa. The NMW rises every April.
They wanted 26k and not the 18.6 when they first brought in the changes in 2012. Both figures to do with the new welfare benefit called Tax Credit (that will have ended by next year for obvious reasons).
Over 18k that tax year between them meant the claimant couldn't claim the extra money for a partner via the second element part of Tax Credits.
The 26k (ish) earnings between them, was the cap for 1 child.
31k (ish) for 2 children.
36k (ish) cap for 3 children. and so on as it went up for each child they had, plus extra rent money for when they had more children.
In 2016, they bought in the 2 child limit for Tax Credits and Housing Benefit (rent). The same for the replacement means tested benefit called Universal Credit, which has different rules and requirements on who can claim and if they can, what they must do for the money they are given.
I'm guessing this 26.2 is above the cap for extra benefit money for one child for a Universal Credit claimant. UC also has the two child limit for extra benefit money.