One of Ralph Kimball's books, The Data Warehouse Toolkit, has a reference
design for a data warehouse for an insurance company.  The schema given in
this book will do exactly what you want.  The book is $30.00 US or so and
well worth the money.  The schema may have been published by Kimball in an
article on the web but I don't have a URL for you.

How is your db set up?  Do you have more than one table?  It sounds like
you'd, at least, need a Personnel table to hold the demographic info
about customers (name, address, DOB, etc.), and a table of their
insurance contracts.  E.g.:

CREATE TABLE Contracts (
  person_id int not null references Personnel ,
  contract_type int not null references ContractTypes ,
  start_date datetime not null ,
  end_date datetime null , -- null means still active
  -- other columns
  CONSTRAINT PK_Contracts
    PRIMARY KEY (person_id, contract_type, start_date)
)

The Contracts table has a start_date & end_date, this will allow you to
make a history of the person's contracts.  If you need to track
something else about a specific contract you can create another table
that has that info w/ start/end dates.  That table would be a history of
changes to contracts.

Obviously, you can keep on creating tables as your specifications become
more particular.  Read a good book on database design.  I usually
recommend _Database Design for Mere Mortals_, by Hernandez.

Here's what I did in one of my applications:

1. I created a copy of each table that I wanted to track, with an extra
date/time field called DateModified. I prefixed these tables' names
with hst, so the archive table for tblClients would be hstClients. You
do need a system to make sure the table definitions say up-to-date.

2. I created a procedure like the following to archive the new version
of a changed record in a form:

 Public Sub ArchiveRecord(fForm As Form, HistTable as string)
   Dim rForm As Recordset, rHist As DAO.Recordset
   Dim fld As Field
 On Error GoTo ErrHandler

   '   Copy new data to history table
   Set rForm = fForm.RecordsetClone
   If rForm.RecordCount <> 0 Then
      rForm.Bookmark = fForm.Bookmark    'find record shown in form
      Set rHist = AdminDB.OpenRecordset(HistTable)

      rHist.AddNew
      '   Use history table for reference of which fields to use,
      '   since form might be based on query
      For Each fld In rHist.Fields
          fld = rForm.Fields(fld.Name)
      Next
      rHist.Update
   End If
 ExitLabel:
 On Error Resume Next
   rHist.Close
   rForm.Close
   Set rHist = Nothing
   Set rForm = Nothing

   Exit Sub

ErrHandler:
'    <error handling code here>
   Resume ExitLabel
End Sub

3. In the after update of the form (e.g. for the table tblClients):
   ArchiveRecord Me, "hstRatesGeneral"

If I were to write this today, I might generate and execute a SQL
statement, instead of using the AddNew method. But this works fine.

Jerry