Though this report was published in 2004 and you could judge the percentage of the decline of English at this year 2012.
Many still think English will be on hold eventhough Dr Nicholas Ostler have mentioned in his book, ther are still many do not read. A large part of whom are no able to read English report and have to rely on the translation
Long gone is the idea, first suggested in the 19th century, that the entire world will one day speak English as a "world language." In fact, the relative decline of English is continuing. In the mid-20th century, nearly 9 percent of the world's population grew up speaking English as their first language. In 2050, the number is expected to be 5 percent.
In the future, the study predicts, most people will speak more than one language and will switch between languages for routine tasks. Monolingual English speakers may find it difficult to fully participate in a multilingual society.
"Native English speakers—particularly monolingual ones—have been too complacent about the status of their language and the lack of need to learn other languages," Graddol said.