Landline to mobile: telephone numbers in the porting database

The statistic depicts the landline to mobile telephone numbers remaining in the porting database at the end of each quarter 2003 to 2009 in the United States. In the 4th quarter of 2008, there were 2.3 million telephone numbers remaining in the porting database.该统计数据描绘了2003年至2009年每个季度末美国港口数据库中保留的固话至移动电话号码数量。在2008年的第四季度，港口数据库中剩余的移动电话号码达到230万。