Question: I have a Crystal Report with about 9 different groups and wanted to be able to have a summary that involves dividing one value by the other.

For example (table):

```
Period    Company   Division   Region  State   City   Store   Employee   Sales   Goal
01-2012   Ab Works  Northern   NW      OR      Ball   888     Foo        100     150
01-2012   Ab Works  Northern   NW      OR      Ball   888     Choo       175     120
02-2012   Ab Works  Southern   SE      GA      Chip   743     Bar        34      75
02-2012   Perrywee  Northern   NC      MN      Fedd   147     Bill       80      64
03-2012   Perrywee  Eastern    FE      WV      Wood   98      Tim        75      250
01-2012   Perrywee  Eastern    FE      WV      Wood   92      Karl       84      250
01-2012   Perrywee  Western    W       CA      Fub    398     Fubar      175     170

```

My output then looks like this:

```
Company   Jan2012   Feb2012   Mar2012 ...  YTD-Avg
Ab Works  70.3%     87.3%     87.5%        84.3%
Perrywee  93.5%     97.3%     130.3%       90.4%

```

Each will allow drilling down to the group below it and the value is calculated by the sum of sales for the group divided by the sum of goals for the group. As there are 14 periods and 8 groups I want to avoid having to create ~115 formuals.

Is there an easy way to accomplish this?

Answer: 
APK files in Android are world-readable by default, so storing sensitive data in there is not a good idea. On JellyBean and later, the app can be forward-locked (aka 'app encryption') which will ensure that your private assets cannot be read by other applications. This is done automatically for paid apps. 

The best way would be to not store the data in the APK but download it on first install. You can use Google Play expansion files, which require authentication to download or come up with your own solution. 

You could store them in some encrypted form and then decrypt them on first run, but then you will have key management issues.
As luck would have it I was reading about this today. The Android Dev guide suggests that you use internal storage for private data as it is inaccessible to other apps or the user. See <http://developer.android.com/guide/topics/data/data-storage.html#filesInternal>
I hope that helps.