"have gradually shifted" is a correct and usable phrase in written English.
It is typically used to describe a gradual change or movement over time. Here is an example: Over the years, the demographics of this neighborhood have gradually shifted, with more and more young families moving in and older residents moving out.
The characteristic peak of the –OH group of alginate observed in scaffold 5 at 3239 cm−1 was observed to have gradually shifted in scaffolds 1, 2, 3, and 4. A gradual shift of carboxyl (–COOH) bands of alginate was also noted from 1411 cm−1 as observed in the spectra of scaffold 5 to 1424, 1429, and 1443 cm−1 in scaffolds 2, 3, and 4, respectively.
Local officials also complain that their bosses, particularly from the regional government, in Seville, have gradually shifted their financial obligations onto municipalities.
Charles Ellis, author of the recent book on Goldman, thinks traders' focus has narrowed as rewards have gradually shifted from the team and the year to the trader and the individual trade.
The world's largest pharmaceutical companies, as their profit margins come under pressure and the cost of getting drugs approved has increased, have gradually shifted some of their research and development activities to outside contractors.
But in the aftermath of the Kosovo war, Mr. Milosevic's international indictment and the rise of his domestic opponents, Mr. Li and other Chinese officials have gradually shifted the stress of their public pronouncements, stressing the common interests linking China and Yugoslavia rather than singling out Mr. Milosevic for praise.
AS a consequence, countries that at different times in history were among the world's great powers, such as Sweden, the Netherlands, France, Britain and Germany, have gradually shifted their sights, either in the wake of defeat or after protracted periods of grappling with decline, from winning the great power sweepstakes to topping lists of nations offering the best quality of life.
But that position has gradually shifted.
Josh: We've gradually shifted our lifestyle over time.
With unemployment rising in France, public opinion has gradually shifted on this and similar issues.
In response, China has gradually shifted its approach, even if family planning policy remains mostly unchanged.
Last summer, Russia threatened to veto the proposal but has gradually shifted ground since Sept. 11.
