Friday's new job numbers offered some good news, with more people finding work despite the unemployment rate ticking up. But it also continued a bad trend: the black unemployment rate was more than twice that of whites.

That disparity is a very, very old one. Since the government began collecting separate data in 1972, the black unemployment rate has always been higher than the white unemployment rate. Every month. In fact, the black unemployment rate has always been at least 60 percent higher than the white unemployment rate. Always. You can use it as a guide: if the white unemployment rate was 5 percent, you know that the black unemployment rate was at least 7.5 percent.

The closest the two unemployment rates have ever been was in August 2009, right after the recession (officially) ended. But even then, the rate for black Americans (14.8 percent) was two-thirds higher — 66.29 percent — than than for white Americans (8.9 percent). In part, that's a function of the unemployment rate for whites being so high. Since February 1972, the first month for which data on both races is available in the Federal Reserve's data system, the black unemployment rate has been over 10 percent more than three-quarters of the time.

In fact, over the course of the 501 months covered by that data, the black unemployment rate has been at least twice that of whites 81.44 percent of the time. More than four out of every five months over the last 42 years, twice much of the black population has been out of work as the white population. (Incidentally, the highest point was 25 years ago last month, February 1989, when the ratio was 176 percent.)

Here's a graph of the ratio over time. The "100%" on the left axis indicates that the black unemployment rate is at least 100 percent higher than the white rate — in other words, twice as much. Every time the blue line is above that "1" line, the black unemployment rate was twice that of whites.