Keyword Analysis & Research: what does not valid mean

Keyword Analysis

Keyword	CPC	PCC	Volume	Score	Length of keyword
what does not valid mean	1.43	0.3	1560	66	24
what	0.78	0.5	1480	61	4
does	1.59	0.6	8086	36	4
not	0.36	0.4	4656	56	3
valid	0.35	0.7	5177	73	5
mean	0.86	0.7	1722	81	4

Keyword	CPC	PCC	Volume	Score
what does not valid mean	0.37	1	3426	55