We've heard about the Northern Powerhouse - whatever happened to the Midland one?

The shiny metal curved roof of Grand Central shopping centre above Birmingham New Street station Image copyright Getty Images

Yesterday, at 7.30am, the first train of the day came to a stop at Birmingham's New Street Station.

Not usually, it must be admitted, a cause for too much celebration. "Train arrives on Sunday" is not much of a headline.

But yesterday was a little different for New Street Station, Britain's busiest outside London.

After a five year, £750m overhaul, Network Rail unveiled the new interchange which now looks more like an airport.

And for those who are keenly hunting for evidence that the UK economy is finally rebalancing away from the hothouse that is London and the South East of England, it was an important moment.

Infrastructure investment is directly linked to economic redevelopment. Just ask those around King's Cross and St Pancras stations in London.

Birmingham's cheer leaders believe New Street will be no different.

Later this week, the new Grand Central shopping centre will open above New Street, one of the largest shopping centres to be unveiled in Europe this year.

The anchor tenant is John Lewis, whose managing director, Andy Street, is also head of the Birmingham and Solihull enterprise partnership.

He says that Birmingham and the West Midlands have turned the corner since the 2008 recession, which saw the region the hardest hit across Britain.

New figures on economic output appear to back him up.

As does the arrival of HSBC's UK bank headquarters - which will open in Britain's second largest city in 2018.

And the continued expansion of Midlands car manufacturer Jaguar Land Rover which has invested £11bn since 2008 and employs 36,000 people.

"Gross value added" per head is the economic value of the goods and services produced in an area, divided by the total population.

It reveals how well an area is performing economically.

Figures from the Office of National Statistics reveal that in 2008-9, GVA in the West Midlands (which includes Birmingham) fell by 3.8%, the most rapid fall of any region in Britain.

The average across England was -2.2%.

The most recent figures available - for the year 2012-13 - reveal a changed picture. West Midlands GVA grew by 2.8%.

That's higher than the England average (2.6%), London (also 2.6%) and the South East (2%).

In terms of rebalancing the British economy geographically, the figures show progress. The North East, North West, West Midlands and Wales all grew faster than London - although of course from a much lower base.

As with all urban areas, there is still a long way to go.

Don't forget, Birmingham was the first location for the documentary series Benefits Street, which revealed the sometimes stark reality of life for those dependent on welfare benefits in Winson Green, a deprived area of the city.

And if the economic figures are studied over a 15 year time frame, a more mixed picture emerges.

A Deloitte report for the local enterprise partnership says that between 2001 and 2015, the West Midlands saw 152,000 net jobs created (that's the surplus of jobs created over jobs lost).

That's fewer than in the East Midlands, Yorkshire and the Humber, the North West, the South East and Scotland.

London, which has a much larger population, enjoyed a far higher number of jobs created - 870,000.

The South East ran it a close second with 845,000.

For the West Midlands the new jobs delivered £6.1bn of fresh wage income, undoubtedly an economic shot in the arm.

But that compares to £30.9bn in the South East, £30.1bn in London, £10.6bn in Scotland and £8.3bn in the East Midlands.

And shows the difficulty of rebalancing the economy when you have such a large powerhouse sitting in the south-east corner.

Fresh income tends to flow towards it.

If we look at the GVA figures over the same 15 year period, the West Midlands saw a 16% increase.

That compares to Merseyside, up 39%, the South East, up 37%, and Wales, up 31%.

Of the nations and regions across Britain, only the North West saw a lower increase, up 14%.

Which shows, despite many positive figures, Birmingham and the surrounding region still have a lot of ground to make up.

And rebalancing the UK economy will be an awfully tough job.