Do you mean that Scotland has voted Conservative in 6 general elections? If so, with a maximum of 5 years between elections, they voted for a Conservative govt for up to 30years of those 38. That's quite a misleading way to represent that statistic isn't it?
Is the 6 times: 6 parliaments or 6 years? Is the 68: 68 parliaments or 68 years? Are units being mixed for exaggeration?
Granted it didn't change the ruling party, however our system isn't just the ruling party there is also the consideration of the majority of the house.
From the linked source on your page [1] we see: 41 Labour MPs were sent to Westminster 11 Liberal Democrats 1 Conservative
From the overall election we know that there was a total of 646 MPs in Westminster [2]. So combine the (41 + 11) - 1 is a combined swing to a Conservative majority in the House of Commons. That's giving the Conservatives about an 8% greater majority.
Whilst Scotland didn't pick the Westminster parliament, they certainly had a hand in providing opposition to any Conservative government.
[1] http://en.wikipedia.org/wiki/2005_United_Kingdom_general_ele... [2] http://en.wikipedia.org/wiki/United_Kingdom_general_election...