The lead in the U.S. Senate election changed hands only once. Norm Coleman's election night margin gradually dwindled, while the lead Al Franken took in mid-December has held firm and grown. Here's how the numbers have shifted:

Nov. 4: Election Day.

Nov. 5 (morning): Coleman by 725

The first unofficial lead, a tiny margin out of 2.9 million votes cast, prompts Coleman to declare victory the morning after Election Day.

Nov. 5 (evening): Coleman by 477

As county officials review vote counts, Coleman's margin shrinks.

Nov. 6: Coleman by 236

As vote tallies around the state continue to be adjusted, the margin narrows, then grows and finally shrinks again. Coleman's lead is cut in half, owing to human errors like one in Partridge Township, Pine County, where exhausted officials mistakenly entered 24 votes for Franken rather than 124.

Nov. 10: Coleman by 206

The margin continues to fluctuate as vote totals are corrected.

Nov. 17: Coleman by 215

Coleman picks up some votes from a post-election audit of about 200 precincts, done to check the accuracy of voting machines. His lead of 215 votes is the unofficial margin confirmed by the state Canvassing Board as it begins the official state recount.

Dec. 5: Coleman by 192

Coleman hangs onto his lead as the hand recount ends and the state Canvassing Board prepares to judge thousands of disputed ballots that have been challenged by both candidates.

Dec. 19: Franken by 251

After the Canvassing Board spends several days reviewing disputed ballots, Coleman's long-held lead disappears and Franken jumps ahead for the first time.

Dec. 30: Franken by 49

Franken's lead drops after the Canvassing Board approves the final allocation of disputed ballots for which challenges were later withdrawn.

Jan. 3: Franken by 225

Franken's lead grows again after the state Canvassing Board counts 933 absentee ballots that both campaigns agreed had been wrongly rejected. Two days later, the board certifies Franken's 225-vote lead -- ending the recount, but prompting Coleman to challenge the outcome in court.

April 7: Franken by 312

The three judges hearing Coleman's appeal allow the counting of 351 additional improperly rejected absentee ballots, which provides a final boost for Franken. A week later, the judges declare Franken the winner of the U.S. Senate election by 312 votes, triggering Coleman's appeal to the state Supreme Court.