Handicap Calculation for David Asher for Week 19

Week of Rounds Used:		18	17	15	14	13		Total		Average		90%		Rounded to:
Gross Score:		58	55	57	54	57		281		56.20
Hdcp Score (over Par):		20	17	21	18	19		95		19.00		17.10		17

What does this mean? How are handicaps calculated?
Handicap Projection for David Asher for Week 20

If your next round score is:		Your new Handicap will be:
40-45		15
46-50		16
51-56		17
57-61		18
62-67		19