Note 8 - Concentration of Revenue (Tables)

6 Months Ended

Jun. 30, 2018

Notes Tables

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

	Three Months Ended June 30,						Six Months Ended June 30,
	201 8			2017			2018			2017
Customer A		4.4	%		8.9	%		4.9	%		10.6	%
Customer B		7.0	%		9.1	%		7.2	%		11.3	%
Customer C		15.2	%		46.6	%		17.6	%		35.1	%
Customer D		39.8	%		−	%		34.0	%		−	%