‍Salary Survey Extra is a series of dispatches that give added insight into the findings of both our annual Salary Survey and our smaller Salary Survey PLUS polls. These posts contain previously unpublished Salary Survey data.

Hollywood loves a good fight night and tends to crank out a new boxing movie every year or couple of years. Sometimes the fighters are fictional, and sometimes the film spins its yarn about an actual boxer. Earlier this year, moviegoers were treated to Hands of Stone, a film about Roberto Durán starring Edgar Ramirez and Robert De Niro; and next month brings Bleed for This, a movie about Vinnie Pazienza (who, among his other bouts, boxed and beat Durán twice) starring Miles Teller and Aaron Eckhart.

As anyone who's ever seen a boxing movie could tell you, there's typically a stretch of the film devoted to the training and string of victories against lesser opponents required to line up the hero with his first big break (or last big comeback, or whatever). You don't become a champion overnight after all, whether in the movies or in real life. It only took Mike Tyson 21 months from his professional debut to his first championship belt, but he still had to win 28 fights to get there. Muhammad Ali had to win 19 fights across 3 years to get to Sonny Liston.

Just like in boxing, you don't simply finish school, or get a certification, and start cashing big paychecks right away. As past salary surveys have shown, the correlation between work experience and salary is about as simple and direct as these things get. The longer that you work in a given sector of the IT realm, the more you earn. If you're just starting out, then your salary is likely to be modest, whereas if you've been in the game for a decade, then your compensation is probably pretty comfortable.

The data from our most recent Salary Survey PLUS, which focused on networking certifications, provides further evidence for what we've started calling the "experience curve." If you can manage to stay employed and keep working — a prospect that's far from guaranteed in IT, as evidenced this week by layoffs at Google and Twitter — then the strong likelihood is that both your earning power and actual compensation will steadily increase.

We compiled our latest set of number by drawing a line between networking professionals in the United States, and those employed elsewhere. For both groups, we tracked average annual salary over the first 10 years of professional networking employment. Here's what the data reveals:

For U.S. networking pros, the pattern seems to be one of rapid salary gains over the first four years of employment, followed by more incremental, if still consistent gains. The reverse is more likely to hold true in non-U.S. countries, where salary accrues slowly at first, with big gains popping up down the road.

Wherever you live and work, don't let frustration push you out of the ring. The longer that you hang in there and keep fighting, the more secure you are likely to become as time passes.