Beta-plus (Î² +) radiation is the emission of positrons, which are the antimatter form of electrons. When a positron slows to speeds similar to those of electrons in the material, the positron will annihilate an electron, releasing two gamma photons of 511 keV in the process.
The Congressional Budget Office puts the cut-off lower, at $347,000 in 2007, or $252,000 after subtracting federal taxes and adding back transfers. Measured by net worth, rather than income, the top 1% started at $6.9m in 2009, according to the Federal Reserve, down 23% from 2007.
According to bureau statistics, top earners garnered an annual salary of $148,670, while those in the bottom 10 percentile only earned $53,130, with the mean annual wage listed at $96,370 for the same period. Salaries also vary based upon the state in which the product manager works.