How to display a query of managers whose salary has not changed over the past 2 years?

Question

Oracle

Good afternoon, there is a managers table with fields:
managerpositionid,
managerid,
datestart (date of employment),
positionid (bank branch),
salary (salary).
At the date of employment, the manager has one salary, and increases over several years of work.
How to display a query of managers whose salary has not changed over the past 2 years?