I think it was of the 36,000 original season ticket holders from our first season at The Etihad only 12,000 remain with "unbroken service" throughout that time. Bearing in mind we generally lose 2,000 season tickets at each renewal that probably stacks up.
As another poster mentioned what is worrying though is the demographic time-bomb we face given the age profile of our support. A lot, like you and me Mike, are in their 50s and are products of the Mercer-Allison era. That generation of support is slowly naturally approaching it's sell by date in terms of match attendance. Cheap pricing for iconic games, like a CL QF, allowing whole families to attend is vital in terms of capturing the next generation. Ultra cheap tickets for students, many of whom aren't from the area, don't support City and won't stay in (greater) Manchester post graduation isn't the answer.
We are aiming to broaden our supporter base outside of the local area and there is nothing wrong with that: we are growing as a club. What is disturbing though is that club figures say that season card holders in Greater Manchester have dropped from 68% a few years ago to 49% this season. Actual sales have increased from 36,000 to 40-42,000 (depending on whether you include premium seats or not) but sales to "locals" have clearly dropped in absolute as well as percentage terms. We are slowly seeing our core support squeezed out. Surely that is not just wrong but incredibly short sighted? This is support that we need to rely on for decades to come in good and bad times.