attrition

attrition [ uh'-TRISH-uh'n ]
[ noun ]

MEANING :
1. a decrease in size, numbers or strength
2. a gradual reduction in work force without firing of personnel, as when workers resign or retire and are not replaced
3. the act of abrasion or a wearing down or away by friction
4. imperfect contrition or repentance for sin motivated by fear of punishment rather than by love of God

USAGE EXAMPLE 1 :
The HR executive informed the directors at the board meeting that the rate of attrition was high because salaries paid by the company were the lowest in the industry.

USAGE EXAMPLE 2 :
Since our original announcement, the economic downturn has reduced the level of natural attrition.