'swiftly increasing' is a correct and usable phrase in written English.
You can use it when referring to something that is happening or growing very quickly. For example, "The popularity of the band is swiftly increasing, with their music streaming records being broken daily."
TNK-BP took advantage of high crude oil prices and grew swiftly, increasing production 14percentt in 2003.
This is the Putin model, or the Beijing model — forget about ephemeral concepts like free speech and pluralism in exchange for a swiftly increasing G.D.P.
They are there as a way of swiftly increasing the level of pain among Palestinians, in the hope that Palestinian leaders will then deal more effectively with militant groups.
This is a great addition to their swiftly increasing number of relevant products.
I couldn't stop laughing/vomiting for the next five minutes as my children looked on in sheer horror, the swiftly increasing future debt for counselling painted on their faces like my vomit on the shoes of the quiet, wide-eyed girl in the front row.
This annual business plan calls for a year of slow but steady growth, followed by a year of swiftly increasing sales.
Once sanctions are lifted, Iran plans to swiftly increase its oil exports.
He swiftly increased the cooperative's milk production, but to expand it further he needed a scientific breakthrough.
He added that the government would focus on creating a pro-business environment that would swiftly increase spending.
Psifidi says she is confident Odyssea will be able to swiftly increase the size of its operation now the relevant permissions have been secured from the island authorities.
Mr. Brennan flew to Saudi Arabia within a week to see him, and the United States swiftly increased its electronic eavesdropping and other spying in Yemen.
