Shipments of optical scanners rose by over 300 percent in 1987 to some 39,000 units, generating total revenue over $110 million. Optical scanner shipments are projected to grow 63 percent per year between 1987 and 1991 to total about $645 million. Maturation of optical scanner technology has led to increased sales. Today about 80 percent of documents can be successfully scanned. In 1981 only five percent of documents could be read. Image scanners are available for around $2,000. Optical character reader shipments are expected to fall by ten percent per year through 1991.