Retailers reported moderate gains in their November sales, as much because of their sales of a year earlier being so bad as that shoppers were getting a head start on buying their holiday gits.

1) of their sales of a year earlier being so bad as that
2) of their sales a year earlier having been as bad as because
3) of their sales a year earlier being as bad as because
4) their sales a year earlier had been so bad as because
5) their sales of a year earlier were as bad as that