Percent Time

Percent Time shows the percentage of run time during which the central processing subsystem (comprising one or more CPUs) was in use by application tasks executing within the measured job step and the percentage of run time during which the central processing subsystem was available but was not in use by application tasks executing within the measured job step.

Execution gives the percentage of time during which the central processing subsystem (comprising one or more CPUs) was in use by application tasks executing within the measured job step. Strobe computes the value as the ratio of samples in which it observed one or more sites of execution to the total number of samples taken. A high execution time percent alerts you to focus on CPU reports within the Profile.
Wait gives the percentage of time during which the central processing was available but not in use by application tasks executing within the measured job step. The value is the ratio of wait samples to total samples. A high wait time percent alerts you to focus on wait reports within the Profile.
Runtime Margin of Error gives the margin of error for the percentages shown in the Performance Profile reports at a confidence level of 95. The reports in the Profile that detail run time are reliable within a range of plus or minus the Runtime margin of error percent reported. A runtime margin of error of less than 2% usually reflects a reliable measurement. Check that this value is 2% or less to verify that you have collected enough samples to have a valid measurement.
CPU Margin of Error gives the margin of error for the percentages shown in the Performance Profile reports that detail CPU time, at a confidence level of 95%. The CPU margin of error signifies that the reports that detail CPU time are reliable within a range of plus or minus the CPU margin of error percent reported. If the Profile has a very low execution time percent, the CPU margin of error will be high. This does not mean that the Profile is invalid. Rather, it indicates that you should focus your analysis on the reports that detail wait time.
Wait Margin of Error gives the margin of error at a confidence level of 95% for the percentages shown in the Performance Profile reports that detail wait time. The percentage signifies that the reports that detail wait time are reliable within a range of plus or minus the percentage reported. A high wait margin of error does not mean that the Performance Profile is invalid. Rather, it indicates that you should focus your analysis on the reports that detail CPU time.

More about the Measurement Session Data report