Where's the best place to represent to become a Minister?

Over the last 40 years (from Ted Heath's government in 1970, so taking in 22 years of Conservative government and 18 years of Labour) the South East of England (with 47) is clearly the best place to reach Minister of State rank. At Cabinet rank things are slightly different, with London having more MPs (25) reaching Cabinet than any other region. At both ranks, the top 3 regions, in absolute terms, are London, the South East and the North West. Perhaps not too much of a surprise, as they're the three biggest regions.

Adjusted for size (based on the number of MPs in each region), not much changes. The top 3 regions at Minister of state level are still the South East, North West and London. It's a bit different at Cabinet, where the North East comes out top (until 1997 there'd only been two Cabinet ministers representing the North East, the last 12 years have added a further 9 to that total) and the East of England ties with London, largely due to the 10 year period between 1987 and 1997.

The worst places places at Minister of State level, both in absolute and proportional terms, are Wales and the North East, with only 12 and 9 MoS over that 40 year period, quite a few of the Welsh Ministers having only served in the Welsh Office. At Cabinet level, its the Midlands regions and, again, Wales, which elect fewest Cabinet members: just 8 (Wales and the East Midlands) and 9 (West Midlands).

My full spreadsheet on this is at www.mapsstatsandpolitics.talktalk.net/regions.xls

Why does any of this matter? In one way it reflects the party strengths in different areas of the country: but with the 40 year span and both parties in government for about the same length of time, that should be cancelled out. But if one of the strengths of our governance system is that everyone in Cabinet also has to answer to a set of constituents so they're in touch with real life, where those constituents are does begin to matter.

It begs question as to why some regions have had twice as many (per head of population) Ministers of States and Cabinet members as others. Is it a reflection of the government system, or the calibre of members from those regions?