P1/P99 (P5/P95, P10/P90) range: 

The difference between P1 and P99 (P5 and P95, P10 and P90) percentiles. RiskyProject presents such ranges as part of results for Monte Carlo simulations for project and for tasks. 

See Also:

Range

Standard Deviation

Variance

Semi Standard Deviation

Kurtosis

Statistical Distribution