Delays vary from device to device, however a general idea of delay can be shown graphically:
Two things to note from the above graphic
(1) Delay always increases as the supply decreases. In other words, the device becomes slower at lower operating voltages.
(2) Families designed for lower-voltage operation will have a flatter curve at lower voltages than those designed for higher-voltage operation. In other words, delay will be more consistent for fluctuations in VCC.