V$SQL_BIND_CAPTURE displays information on bind variables

In Oracle documentaion, it stats that:

DBA_HIST_SQLBIND displays historical information on bind variables used by SQL cursors. This view contains snapshots of V$SQL_BIND_CAPTURE.

It seems to me that DBA_HIST_SQLBIND doesn't store all historical bind variables information since it only contains snapshot of V$SQL_BIND_CAPTURE.

1. I wonder how often the snapshot has been taken?

2. Is there other way to find all historical bind variables information?

Thanks in advance.