Why is there no KF_ANSWER_STATS data before a specific date?
All sites that updating through November 2011
No data will exist in these tables previous to your site update which contained the November 2011 version.
Note that portions of these tables are purged according to the KF_ACTIONABLE_DATA_PURGE_DAYS configuration. The default for this setting is 45 days.
The following tables were added in November 2011:
There is no functionality in older versions that exactly matches what is stored in these tables and there is no way to build the data from previous versions. However, there is information on end user visits and answer views in the STATS and ANS_STATS tables. Refer to the standard reports that reference these tables and the data dictionary for more information.