(CN) – Former Vice President Joe Biden continues to lead the field of Democratic contenders for president nationally despite a gradual drop in support over the last year, according to new polling data.

A CNN poll released Thursday reveals Biden enjoys support from 26% of Democrats and Democrat-leaning independents nationally. The poll gives Biden a six-point advantage over his closest rival Vermont Senator Bernie Sanders, who holds 20% support.

Close behind Sanders in third is Massachusetts Senator Elizabeth Warren at 16%, while South Bend, Indiana, Mayor Pete Buttigieg takes fourth with 8% support. Former New York City Mayor Michael Bloomberg rounds out the top five at 5%.

No other candidate topped 5% support in the CNN poll, though a trio of candidates – businessman Andrew Yang, Minnesota Senator Amy Klobuchar and New Jersey Senator Cory Booker – are tied for 6th place with 3% each.

These numbers suggest the Democratic presidential primary has undergone some notable changes as the race took shape over this past year, changes that have been far kinder to some candidates than others.

For Biden, despite being in the lead, Thursday’s poll reveals a dip in support compared to his standing at the end of last year. In December 2018, CNN released a poll that had Biden commanding a third (33%) of Democratic support, seven points higher than the support he maintains now.

Sanders, for his part, has experienced a notable bump in support compared to where he was a year ago. The end-of-year 2018 poll had Sanders at 14%, six points lower than the 20% support he enjoys today.

The candidate who has seen the most change compared to last year, however, is Warren. The senator saw her support quadruple from 4% at the end of 2018.

Buttigieg and Bloomberg had not entered the race at the time the 2018 CNN poll was taken.

The December 2018 poll also serves as a reminder that two candidates who enjoyed top spots in the Democratic primary then are no longer in the race. California Senator Kamala Harris and former Texas Congressman Beto O’Rouke both commanded places in the top six a year ago but have since suspended their campaigns.

Another element in the race that shows signs of change are what Democrats are prioritizing when choosing their candidate. Thursday’s poll reveals that 47% of voters believe having a candidate who can defeat President Donald Trump in the general election is more important than having a candidate who shares their values and political positions, the lowest number of voters to express that sentiment so far.

Polling data suggests that the candidate who could be most affected by this drop is Biden, who continues to be the candidate voters believe has the best shot at overtaking Trump. A sizeable 40% of Democratic voters say Biden tops the field when it comes to electability, a double-digit advantage over his Democratic rivals in this regard.

Nearly the same number of voters (37%) say that Biden is also the candidate who could unite the nation after what is likely to be a highly contentious general election.

On more personal issues, however, voters give Sanders the top spot. Over a quarter of voters believe that the senator is the candidate who most shares their values, as well being the candidate who is the most honest and empathetic.

Despite the standings of each candidate on these issues, the CNN poll reports that voters across the board are becoming more enthusiastic as the race continues. About half of all registered voters say they are “extremely enthusiastic” about casting their presidential ballots next year, the highest voter enthusiasm statistic CNN polling data has ever reported.

This enthusiasm is growing among both Republicans and Democrats. Democratic enthusiasm has jumped from 46% to 58% compared to last month, while Republican enthusiasm has increased from 52% to 59%.

These numbers come in on the day CNN is set to air the final Democratic presidential debate of 2019.

The CNN poll surveyed 1,005 adults and has a 3.7% margin of error.