This page lists all alliances of sufficient size and provides various statistics - the alliance's name, its title, how many members it has, the average networth of all members, and the summed networth of all members.
Clicking on a alliance's name will list all of its members (using the Search feature).
The column headers for Members, Average Networth, and Total Networth can be clicked to sort the table descending by the respective attribute.
Additional statistics are listed below this table - the number of alliances (and overall percentage) which had too few members to be listed, and the number of dominions (and overall percentage) which are not members of a clan.