(Children have seen a rise from on average £1.13 a week to £6.35, but over the same period, the typical annual wage for working adults has increased by just 188%, from £11,648 in 1987 to £33,511 in 2014.
I think the difference is that children aren't afraid to ask for a rise. After all, no one is going to sack them because they cost too much, are they?)