You can't. There is no way to speed up the process. If no editor desires to review the sites in your category of interest, it could wait forever and never get reviewed. There is nothing in the system that forces editors to review sites in any category.
There are internal "Help Wanted" notices, where volunteers are asked to go work on categoires that have not been actively edited, but it's a totally volunteer effort.
Note that one year waiting of waiting to be reviewed is not considered seriously backlogged by anyone.