This is the number of route update entries queued up and waiting to be sent out this specific interface. A persistently high count here during steady-state operation, not right after a topology event, suggests the interface's EIGRP process cannot drain its update backlog, which delays how quickly downstream routers learn about network changes. Seeing this value hold at 200 for minutes after a single link failure elsewhere would indicate this router is bottlenecking route propagation rather than passing updates through promptly.