During the same period, smartphone ownership increased from 16.8 percent to 27.0 percent, while 3G/4G phone ownership reached 51 percent in December 2010. Note: Due to an interface glitch, earlier copies of this chart from the U.S. Digital Year in Review and Mobile Year in Review contain figures that slightly vary. This issue has been corrected and the accurate figures are reflected in this data gem as well as updated in both versions of the downloadable reports.