BacklogOrders remained strong across the company with a consolidated book-to-bill ratio, defined as orders divided by revenue, of 0.9-to-1 for the quarter and 1-to-1 for the year. The company ended the year with backlog of $90.6 billion and estimated potential contract value, representing management's estimate of additional value in unfunded indefinite delivery, indefinite quantity (IDIQ) contracts and unexercised options, of $53.4 billion. Total estimated contract value, the sum of all backlog components, was $144 billion at year end, up 9.1% from a year earlier.