These graphs represent the number of keys in the litecoin blockchain containing a balance of at least the amount specified over time. They give an indication as to how many people are using litecoin and how many litecoins they have. Check out the LTC topowners report now updated daily.
note: The data between Jun 20th and Jul 9th is wrong.. the datafeed stalled.. it will be fixed when I get around to it. Also any point where the graph data is 0 is an error..