Keyword Analysis & Research: what does the number 21 represent

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
what does the number 21 represent	0.85	0.6	7159	78	33
what	1.4	0.7	4868	47	4
does	0.82	0.5	4172	92	4
the	0.5	0.4	3435	64	3
number	0.89	0.3	8380	3	6
21	1.39	0.7	4594	82	2
represent	1.52	0.6	9513	69	9

Keyword	CPC	PCC	Volume	Score
what does the number 21 represent	0.68	1	5174	11