U.S. retail sales rose 0.9 percent in the week ending on Christmas Eve and jumped disproportionately higher than the same week of 2010, a trade group said. The International Council of Shopping Centers deemed the 0.9 percent week-to-week rise a \"solid\" gain for retailers. The final week of the retail marathon that began Black Friday provided \"evidence of a strong two-week finish to the 2011 holiday season,\" the trade group said. Sales also jumped 4.5 percent over the same week of 2010, but the gain was expected given Christmas was on a Sunday this year, whereas last year Christmas subtracted a day of shopping from the week. The ICSC said online sales were strong on Christmas Day and the day after with electronics and department stores, \"as is typical this time of year,\" reporting their strongest customer traffic for the 2011. Factory outlets also \"remained busy,\" ICSC said. In a survey, shoppers indicated 62.4 percent of their holiday shopping was done in a brick-and-mortar store, while 34.3 percent was done online and 3.3 percent done through a catalog.