Only 27 months have passed since the Ravens hoisted the Vince Lombardi Trophy in New Orleans. They've played just 32 regular-season games since then.

Yet the team that won the Super Bowl barely exists anymore.

None of the running backs who carried the ball for Baltimore that day are still on the roster. Of the five wide receivers and tight ends who caught passes against the San Francisco 49ers, only Dennis Pitta remains.

Overall, only five of the 22 offensive and defensive players who started for the Ravens in the Superdome on Feb. 3, 2013, are still around. That's just 22.7 percent of the starting lineup, according to my calculations. If you can name those five starters, well, nice going. I'll identify them later in this column. (Hint: Three play offense, two play defense.)

Another way of looking at it, of the 53 players who were on the Ravens' roster on Super Sunday, only 13 are still there – 24.5 percent.

I'm bringing it up now because another generation of rookies gathered for a minicamp at the Under Armour Performance Center last weekend, and while it's far too soon to know how many will have roles in the franchise's future, it's a certainty some will, continuing the rapid evolution that began almost as soon as Super Bowl 47 ended.

Research suggests the average NFL roster changes anywhere from 15 to 20 percent per year, so the Ravens have evolved well ahead of the typical pace – more than 75 percent in less than three years.

That almost sounds reckless, but not when you consider the Ravens intentionally fielded a veteran-laden roster in 2012 to take one last shot at the Super Bowl with Ray Lewis, Ed Reed and company. Long before the team coalesced in the playoffs and took its wild ride to glory, GM Ozzie Newsome and the front office planned to engineer a roster overhaul after that season. Regardless of how things turned out, it was time to start getting younger, finding new blood.

I'm guessing the process has gone faster than the organization envisioned. If reserve defensive end DeAngelo Tyson, 26, is on the roster when the Ravens kick off the 2015 season in September, he'll be the only defensive lineman left from the Super Bowl. Jimmy Smith and Asa Jackson will probably be the only defensive backs left. (Lardarius Webb was under contract in 2012 but out of action because of an injury.) Terrell Suggs, Courtney Upshaw and Albert McClellan are the only linebackers still around.

Other than Joe Flacco, the offensive backfield has been wiped clean, completely reinvented. The same is true for the pass-catching corps other than Pitta, who has barely played since the Super Bowl because of hip injuries. On the offensive line, only two projected starters for 2015, Kelechi Osemele and Marshal Yanda, have Super Bowl rings.

The dramatic pace of the Ravens' roster restructuring provides interesting context for their on-field results since the Super Bowl. Some fans might be disappointed that they haven't won another AFC North title, but given the sweeping changes they have undertaken, I say it's impressive they haven't had a losing season.

(FYI, to answer the question posed above, the five Super Bowl starters still in their jobs are Flacco, Osemele, Yanda, Suggs and Upshaw. The special-team trio of kicker Justin Tucker, punter Sam Koch and long-snapper Morgan Cox are also still around.)

Even if things hadn't broken the Ravens' way on the last day of the 2014 regular season and they had missed the playoffs for a second straight year, it's pretty evident why they were in that situation. They've been rebuilding on the run for more than two years, inserting new blood almost everywhere except under center.

Maybe you didn't notice because headliners such as Flacco, Suggs and Haloti Ngata were still around to give the impression of continuity, but the overhaul has been drastic.

Now that Ngata also is gone, the Super Bowl will recede that much farther into the past.

The "new" Ravens are younger, for sure. The average age on the roster was 26.5 years in 2012; by last year it was down to 25.5 and should sink farther this year as rookies such as Breshad Perriman and Maxx Williams find places in the blueprint.

The rebuilding project isn't over, and in fact, it really never ends. But in the wake of their playoff push in 2014, the Ravens are considered serious contenders in 2015. Not bad, considering.