Registered nurses and licensed practical nurses working in long-term care are experiencing pay increases, but some wage gaps still exist between male and female nurses, the results of a new survey show.

Medscape’s 2017 RN/LPN Compensation Report, published Wednesday, surveyed more than 10,000 nurses on their annual earnings and job characteristics. Just over 20% of the LPN respondents worked in skilled nursing or other long-term care facilities, while only 3% of the RNs surveyed did.

Results showed that for RNs working in long-term care, the average wages increased from $74,000 to $77,000 between 2015 and 2016. LPN wages in skilled nursing facilities saw a more modest raise, from an average of $47,000 to $49,000.

Despite those increases, “nursing continues to grapple with an apparent gender wage gap,” the report’s authors wrote. The survey’s findings showed that male RNs earned an average of $4,000 more than female RNs; LPN results showed an average $3,000 gap between male and female nurses. Men also were found to typically be paid more in 2016, regardless of whether they were paid hourly or were salaried.

But overall salary differences don’t necessarily explain all sides of the issue, Medscape reported. The pay differences between male and female nurses appeared to even out for hourly workers, and fewer male nurses responded to the survey.

“An unanswered question, however, is why the hourly rate of pay for men and women is virtually identical when men, on average, have been practicing for fewer years (only 48% of men have worked > 20 years vs 68% of women),” the report reads. “And this still doesn’t explain why salaried male nurses earn more than their female counterparts.”

Click here to read the full Medscape survey, which also includes information on RN and LPN educational degrees, certifications, years of experience, and earnings by region.