According to Math World, Bedford's Law is the tendency in listings, tables of statistics, etc., the digit 1 tends to occur with a probability of ~ 30%, much greater than the expected 11.1% (i.e., one digit out of 9).
It is named after physicist Frank Benford. In 1938 he showed the trend appears in many number sets, from the surface area of rivers to baseball statistics to figures picked randomly from a newspaper. It's also cropped up in investigations of tax fraud, voter fraud and digital data manipulation (most likely from forensic investigations).
A current spin on the law in New Scientist by Malcolm Sambridge of the Australian National University in Canberra sees it in the depths of "almost 250,000 earthquakes that occurred worldwide between 1989 and 2009, the brightness of gamma rays that reach Earth as recorded by the Fermi space telescope, the rotation rates of spinning star remnants known as pulsars, and 987 infectious disease numbers reported to the World Health Organization in 2007." (quoting the New Scientist article)
More at: Curious mathematical law is rife in nature.