The Boston Globe’s paid circulation has grown for the first time since September 2004, according to an independent auditor of newspaper circulation.
Average Sunday circulation was 365,512 for the six months that ended in March, an increase of 2.5 percent compared with the same period a year earlier, according to the Audit Bureau of Circulations. Average daily circulation rose nearly 2.9 percent during those same six months, to 225,482.
The numbers include print circulation and digital subscriptions to BostonGlobe.com, which was launched in October.
“This growth clearly reflects our readers’ dedication to our high-quality and award-winning journalism delivered both in print and across a variety of digital devices,’’ Boston Globe publisher Christopher Mayer said in a statement. “With the largest newsroom in New England, we’re providing the most reliable and in-depth coverage in the region.’’
Nationally, average daily newspaper circulation rose by less than 1 percent, while Sunday circulation rose 5 percent, the Chicago-based Audit Bureau said.
Over the past 18 months, the Audit Bureau has made rule changes to address the newspaper industry’s continuing expansion beyond print, including new ways to audit and report digital editions published on websites, tablets, and smartphones. Under the new rules, circulation numbers may include some duplication between print and digital subscribers.
Tuesday’s report was the first to show year-over-year numbers reflecting the changes.
Average daily circulation at the Boston Herald - which does not have paid digital subscriptions - fell 12.3 percent to 108,548 in the six months ended in March, compared with the same period a year before. The newspaper’s Sunday circulation declined 6.2 percent, to 81,925.
Citing the Herald’s combined print and free online readership, publisher Patrick Purcell said in a statement that the paper “is more popular than ever.’’
On average nationwide, paid digital subscriptions account for 14.2 percent of newspapers’ total circulation, up from 8.66 percent in March 2011. Such digital circulation can include tablet or smartphone apps, PDF replicas, metered or restricted-access websites, and e-reader editions. Branded editions - including newspaper-owned products such as commuter, community, or alternative-language newspapers - make up 4.5 percent of newspapers’ total average circulation, up from 3.36 percent in March 2011.
“This is not only good news, it’s great news for newspapers,’’ said Lou Ureneck, professor of journalism at Boston University.
By including digital subscribers, he said, circulation figures “better reflect the marketplace reality where readers are being counted, whether they are reading online or in print, and these new metrics are showing a strong demand for journalism in our chaotic information environment.’’
That demand was perhaps best exemplified by The New York Times’s dramatic 73 percent increase in total circulation in the six-month report, fueled in large part by digital gains. The Audit Bureau of Circulations said the Times online now has more subscribers than the newspaper’s print version. Average digital circulation was 807,026, compared with print circulation of 779,731, for a total of 1,586,757. The Globe is owned by The New York Times Co.
Ureneck said the increases in readership at many newspapers, even as more are charging for online content, “demonstrate that the decision to erect paywalls now seems to have been a wise and a crucial decision.’’
As of March 18, paid digital subscribers to BostonGlobe.com and the Globe’s e-reader and replica editions totaled about 18,000, up about 13 percent since the end of the fourth quarter of 2011.
In March, BostonGlobe.com and the paper’s free website, Boston.com, together attracted more than 7 million unique visitors, according to comScore, a company that tracks Internet traffic.