Keyword Analysis & Research: what is the unit for number density

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
what is the unit for number density	0.02	0.9	111	83	35
what	0.74	0.7	755	20	4
is	1.5	0.2	6686	24	2
the	0.95	0.7	6367	53	3
unit	0.78	0.9	4999	35	4
for	1.75	0.3	6527	60	3
number	0.48	0.1	5354	17	6
density	0.47	0.6	7519	62	7

Keyword	CPC	PCC	Volume	Score
what is the unit for number density	0.72	0.2	4018	36