Delays of 0, 6, 12, 18, and 24 seconds are tested. The delay is constant within a session but varied between sessions in the following sequence (Monday through Saturday); 0, 0, 6, 12, 18, and 24 s. This 6-day cycle is repeated four times for a total of 24 test sessions. Data from the last two cycles are combined and used for the data analysis. However, the first session of the week (Mondays) with the 0-s delay is excluded from analysis.