This thread sparked my interest to read a little bit more about the development of islamic views of the Indonesian public. It's not possible to compare the data (or rather: the conclusions made by the researchers) from the poll in the OP with other, older data. What we can do, is compare the development of various political parties since the first elections in the post-Suharto era. Increasing support for islamic parties can tell us if the Indonesian society is becoming more islamic, especially if this support is for conservative islamic parties.
The political parties can be divided into two groups, secular parties and islamic parties. There are 5 islamic political parties that are worth mentioning:
- PK(S) conservative, claims to support the implementation syari'a
- PAN progressive, probably most moderate of these 5 parties
- PPP conservative, has islam as it's ideological foundation
- PKB moderate, does not advocate Indonesia to become an islamic state
- PBB conservative, claims to support the implementation of syari'a law
PK(S), PPP, PBB are the more conservative parties.
Simplified conclusion of the above data: since 1999 about 1 out of 3 votes has been for islamic parties, and 1 out of every six votes has been for representatives of conservative islamic parties.