The picture for women and minorities at the nation’s law firms changed only marginally during 2012, with the percentage of female associates declining slightly for the third year in a row, while the number of women and minority group members ticked up, according to NALP.

In fact, the changes were so slight that it took two decimal places to measure them: Women accounted for 45.05 percent of all associates, marking only the third time since NALP began tracking the numbers in 1993 that their percentage has dropped. Last year, their percentage was 45.35.

Women represented 19.91 percent of law firm partners, up from 19.54 percent in 2011. Similarly, minority group members accounted for 6.71 percent of the partnership ranks, up from 6.56 percent last year.

The information, released on December 13, is based on a survey of 1,209 law offices across the country that are members of NALP’s Directory of Legal Employers. Those offices ranged from fewer than 100 attorneys to more than 700. NALP formerly was known as the National Association for Law Placement.

The NALP survey, which tracked women and minorities, uncovered a slight gain in those attorneys among all lawyer jobs at firms. Minorities as a whole made up 12.91 percent of the lawyers — including partners — in these offices in 2012, compared with 12.70 percent in 2011.

The decline in the percentages of women associates indicates a shift in thinking among young women, said Beth Kaufman, president of the National Association of Women Lawyers.

“Every year we see a big drop-off in the number of women at law firms after seven or eight years of practice,” she said. “This is starting to influence the pipeline. They’re asking themselves, ‘If I’m not going to advance and I’m not going to make as much money, is this a profession where I want to be?’ “

NALP noted that the number of women and minorities has climbed slowly at law firms since 1993. The increase, the report said, “has been only marginal.”

Leigh Jones is a reporter for The National Law Journal, a Legal affiliate based in New York.