Explanations

left top: value of characteristic number for a single event.
left bottom: mean value of the characteristic number within the period of data analysis.
right top: maximum value of the characteristic number within the period of data analysis.
right bottom: minimum value of the characteristic number within the period of data analysis.

Examples

ebb current duration:tide current duration	ebb current duration:tide current duration (maximum)

ebb current duration:tide current duration (mean value)	ebb current duration:tide current duration (minimum)