In Turkey itself, a 2002 Gallup poll indeed found that 37% say religion is 'very important', 41% say it is essential to life, and for 27% it is the most important thing in life.

However, the long-term trend is of decrease (tough I only found scant and non-countriwide-sampled data). Two local samples: I found one from the sixties in which 50% preferred the "Turk" identity and 37.5% the "Muslim" one, and one from 1993 in which 69% preferred "Turk", 21% chose "Muslim Turk", and 4% chose "Muslim". A 2000 study of factory workers (on page 9 of this pdf) found a strong decrease with age of those who think prayer at work is important.

In contrast, Muslims/Turks in Germany are less religious.

One 2003 study (pdf!) counts 3,112,000 inhabitants with a Muslim cultural identity, of which 2,365,120 (76%) profess a Muslim religious identity, but only 309,000 (9.9%) are organised. Even in the year after 9/11 and up to the Iraq War, the number of Friday prayer attendants is just 464,000 (14.9%), and that of daily prayers in a mosque 185,000 (5.9%) - not dissimilar to similar numbers in the 'Christian' population! Prior to 9/11, weekly attendance was about 9%, but that was down from 22% measured in a study in the middle of the nineties (see towards the end here).

Furthermore, in a printed source (I forgot where since last year...), I found this further data from that study in the nineties: of under-16 children of Muslims in Germany, 58% have broken with their parents' religious traditions, 12% consider to do so; and of the 42% still holding to the traditions, 22% percent do so at parental pressure. Another 1997 poll for the Berlin local government asked youth of Turkish origin about membership in an assotiation - 23.5% were, but of these, 19.2% were members of sports assotiations, and a mere 0,4% of a religious assotiation.

If I have more time, I'll trawl for more and more recent data (and will put it all in another diary).

_{*Lunatic*, n.
One whose delusions are out of fashion.}