Last week, researchers at Columbia University released a detailed, book-length account of how Texas probably executed an innocent man, Carlos DeLuna, in 1989. This week, a new report from Northwestern University and the University of Michigan "picks up where the DeLuna case left off," says Andrew Cohen at The Atlantic. Focusing on the big picture, researchers from the two schools launched the first-ever National Registry of Exonerations, and their first report takes a stab at cobbling together hard-to-find, rarely publicized stories and statistics about Americans who've been cleared of crimes for which they were convicted but didn't commit. What they found: More than 2,000 people were wrongfully convicted of crimes since 1989. "If that were the extent of the problem we would be encouraged by these numbers," says Michigan law professor Samuel R. Gross. But sadly, it's just the tip of the iceberg. One hope of the registry is to find out where the system messes up, so more innocent people don't end up in jail. Here's a look at some of the key findings, by the numbers:

Total known number of inmates and ex-convicts exonerated of serious crimes since 1989, according to the new report  

400 million
Serious (non-traffic) cases prosecutors have handled since 1989, according to the National District Attorneys Association 

Specific wrongful conviction cases detailed in the National Registry of Exonerations

Percent of the exonerated convicts who are men

Percent who are black 

Average time, in years, from conviction to exoneration

Combined time, in years, the 891 exonerated prisoners spent behind bars

2.3 million
People incarcerated in the U.S.  

Convicted defendants cleared in 13 "group exonerations" since 1995, following large police-corruption scandals, usually involving planted drugs or guns

People exonerated of wrongful homicide convictions 

Percent of those convictions attributed to perjury or false accusations 

Exonerated convicts who had been sentenced to death 

People exonerated of wrongful adult-rape convictions 

Percent of those convictions attributed to mistaken witness identification 

People exonerated of wrongful child sexual abuse convictions

Percent of those cases attributed to "fabricated crimes that never occurred at all" 

People cleared since 1989 due to DNA testing, 222 of them since 2000, according to the Innocence Project 

Defendants cleared by DNA who had spent time on death row 

People exonerated of crimes that never happened 

People exonerated who had confessed to crimes they didn't commit 

Exonerations in Cook County, Illinois (Chicago), since 1989, the most in the country. (The areas with the most exonerations aren't necessarily the ones with the most wrongful convictions.) 

Exonerations in Dallas County, Texas, since 2007, the most in recent years

Sources: AP, Atlantic, Huffington Post, Innocence Project, National Registry of Exonerations [PDF], USA Today, Wall Street Journal, Wrongful Convictions Blog