Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	May 31, 2016	May 31, 2015
Cash Flows from Operating Activities:
Net income	$ 836,134	$ 609,569
Adjustments to reconcile net income to net cash provided by operating activities -
Depreciation and amortization	1,555,283	1,431,823
Decrease in deferred tax asset	495,555	430,763
Stock based compensation	53,424	53,424
Changes in trade accounts receivable	(2,083,158)	501,236
Changes in related party receivables	(80,023)	(306,243)
Changes in inventory	124,849	186,821
Changes in prepaid expenses and other	(50,009)	76,921
Changes in accounts payable and accrued expenses	2,063,010	323,155
Net cash provided by operating activities	2,915,065	3,307,469
Cash Flows from Investing Activities:
Purchase of property and equipment	(4,323,131)	(991,950)
Cash Flows from Financing Activities:
Proceeds from long-term debt	2,530,072
Proceeds from revolving loan	1,675,000	850,000
Payments on long-term debt and capitalized lease	(1,725,631)	(1,904,607)
Payments on revolving loan	(300,000)	(935,000)
Proceeds from exercised stock options	57,000	114,000
Dividends paid on preferred stock	(325,885)	(298,288)
Dividends paid by variable interest entity	(204,000)	(204,000)
Net cash provided by (used in) financing activities	1,706,556	(2,377,895)
Net Increase (Decrease) in Cash	298,490	(62,376)
Cash, beginning of year	598,887	661,263
Cash, end of year	$ 897,377	$ 598,887