This is the number of times the LSP database has become overloaded. It is a historical tally of how many times this router's own link-state database hit an overload condition, so a rising count across multiple incidents suggests the router is chronically under-resourced for the area's actual database size rather than each incident being a one-off. For example, an admin seeing this counter increment repeatedly over a month on an older, smaller router while the area's LSP database has grown would recognize the router itself, not a transient bug, as the recurring cause and plan a capacity upgrade.