Our cash flow provided by operating activities was very strong at $409 million and $437.4 million in fiscal '20 and '19, respectively.
Cash flow provided by operating activities totaled $110.2 million, or 177% of reported net income in the fourth quarter of fiscal '20, as compared to $124 million in the fourth quarter of fiscal '19.
And during the fourth quarter, we experienced increases in consolidated operating income, net income, and net sales of 30%, 15% and 10%, respectively.
In fact, despite the continued impact from the pandemic on demand for our commercial aerospace parts and services, the Flight Support Group's operating income and net sales in the fourth quarter of fiscal '20 improved sequentially by 78% and 9%, respectively, as compared to the third quarter of fiscal '20, a significant improvement.
The Electronic Technologies Group and from now on I will call it ETG, set all-time quarterly net sales and operating income records in the fourth quarter of fiscal '20 improving 8% and 14%, respectively, over the fourth quarter of fiscal '19.
We recently entered into an amendment to extend the maturity date of our revolving credit agreement by one year to November 23 and to increase the committed capital to $1.5 billion.
In addition, our credit facility continues to include a feature that will allow the company to increase the capacity by $350 million to become a $1.85 billion facility through increased commitments from existing vendors or the addition of new lenders and can be extended for an additional one-year period.
Our net debt, which we define as total debt less cash and cash equivalents of $333 million, compared to shareholders equity ratio improved to 16.6% as of October 31 '20, and this was down from 29.8% as of October 31 '19.
Our net debt to EBITDA ratio improved to 0.71 times as of October 31 '20, down from 0.93 times as of October 31 '19.
As we reported yesterday, we declared an $0.08 per share regular semi-annual cash dividend on both classes of common stock, payable January 21, 2021 to shareholders of record as of January 7, 2021.
This cash dividend will be our 85th consecutive semi-annual cash dividend since 1979.
While this is very important to all of our shareholders, it is especially important to our team members, the vast majority of whom are fellow HEICO shareholders through the personal holdings in their 401(k) plan.
First, we acquired a 75% of the equity interest in Transformational Security and Intelligent Devices.
Next, we acquired approximately 90% of the equity interest of Connect Tech.
These acquisitions are expected to be accretive to earnings within the first 12 months following closing.
The Flight Support Group's net sales were $924.8 million in fiscal year '20, as compared to $1,240.2 million in fiscal year '19.
The Flight Support Group's net sales were $193.6 million in the fourth quarter of fiscal '20, as compared to $324.7 million in the fourth quarter of fiscal '19.
Net sales in fiscal '20 follows the 13% and 12% organic growth reported in the year and fourth quarter of fiscal '19, respectively.
The Flight Support Group's operating income was $143.1 million in fiscal '20, as compared to $242 million in the fiscal year '19.
The Flight Support Group's operating income was $21.5 million in the fourth quarter of fiscal '20, as compared to $62.2 million in the fourth quarter of fiscal '19.
The Flight Support Group's operating margin was 15.5% in fiscal '20, as compared to 19.5% in fiscal '19.
The Flight Support Group's operating margin was 11.1% in the fourth quarter of fiscal '20, as compared to 19.2% in the fourth quarter of fiscal '19.
The Electronic Technologies Group's net sales increased 5% to a record $875 million in fiscal '20, up from $834.5 million in fiscal '19.
The increase in fiscal '20 is attributable to the favorable impact from our fiscal '20 and '19 acquisitions, partially offset by an organic net sales decrease of 1%.
The ETG's net sales increased 8% to a record $236.7 million in the fourth quarter of fiscal '20, up from $219.5 million in the fourth quarter of fiscal '19.
The Electronic Technologies Group's operating income increased 5% to a record $258.8 million in fiscal '20 up from $245.7 million in fiscal '19.
The ETG's operating income increased 14% to a record $73.9 million in the fourth quarter of fiscal '20, up from $64.6 million in the fourth quarter of fiscal '19.
The Electronic Technologies Group's operating margin improved to 29.6% in fiscal '20, up from 29.4% in fiscal '19.
The ETG's operating margin improved to 31.2% in the fourth quarter of fiscal '20, up from 29.4% in the fourth quarter of fiscal '19.
Moving on to diluted earnings per share, consolidated net income per diluted share decreased 4% to $2.29 in fiscal '20, as compared to $2.39 in fiscal '19.
Consolidated net income per diluted share decreased 27% to $0.45 in the fourth quarter of fiscal '20, as compared to $0.62 in the fourth quarter of fiscal '19.
Depreciation and amortization expense totaled $88.6 million in the fiscal '20, up from $83.5 million in fiscal '19 and totaled $23.3 million in the fourth quarter of fiscal '20, up from $21.8 million in the fourth quarter of fiscal '19.
R&D expense was $65.6 million in fiscal '20 or about 3.7% of net sales and that compared to $66.6 million in fiscal '19%, or 3.2% of net sales.
R&D expense was $16.6 million in the fourth quarter of fiscal '20, or 3.9% of net sales, and that compared to $17.9 million in the fourth quarter of fiscal '19 and that was 3.3% of net sales.
SG&A expenses consolidated decreased by 14% to $305.5 million in fiscal '20, and that was down from $356.7 in fiscal '19.
Consolidated SG&A expense decreased by 18% to $72.6 million in the fourth quarter of fiscal '20, down from $88.8 million in the fourth quarter of fiscal '19.
Consolidated SG&A expense as a percentage of net sales dropped to 17.1% in fiscal '20, and that was down slightly from 17.4% in fiscal '19.
Consolidated SG&A expense as a percentage of net sales increased to 14% -- I'm sorry, 17% in the fourth quarter of fiscal '20, and that was up slightly from 16.4% in the fourth quarter of fiscal '19.
Interest expense decreased to $13.2 million of fiscal '20 and that was down significantly from $21.7 million of fiscal '19 and it decreased to $2.5 million in the fourth quarter of fiscal '20, down from $5.2 million in the fourth quarter of fiscal '19.
Our effective tax rate in fiscal '20 was 7.9%, as compared to 17.8% in fiscal '19.
Our effective tax rate in the fourth quarter of fiscal '20 was 22.3% and that compared to 19.8% in the fourth quarter of fiscal '19.
Net income attributable to non-controlling interest was $21.9 million in fiscal '20, and that compared to $31.8 million in fiscal '19.
The decrease in fiscal '20, principally reflects a decrease in operating results of certain subsidiaries of Flight Support, in which non-controlling interests are held, as well as the impact of a dividend paid by HEICO Aerospace in June '19 -- 2019, that is -- that effectively resulted in the transfer of 20% non-controlling interest held by Lufthansa Technik in eight of our existing subsidiaries and that was transferred back to our Flight Support Group.
Net income attributable to non-controlling interest was $5.3 million in the fourth quarter of fiscal '20, and that compared to $6.9 million in the fourth quarter of fiscal '19.
For the full fiscal year '21 at the present time, we anticipate a combined tax and non-controlling interest rate of approximately 23% to 24%.
Previously, I mentioned cash flow provided by operating activities was consistently strong at $409.1 million and $437.4 million in fiscal '20 and '19, respectively.
Cash flow provided by operating activities totaled $110.2 million, or 177% of net income in the fourth quarter of fiscal '20 and that compared to $124 million in the fourth quarter of fiscal '19.
We currently anticipate capital expenditures of approximately $40 million in fiscal '21, and that would be up from the $22.9 million spent in fiscal '20.
Our working capital ratio, which is, of course, current assets divided by current liabilities, improved to 4.8 as of October 31, '20, as compared to 2.8 as of October 31, '19.
Days sales outstanding, DSOs of accounts receivable approved -- improved to 45 days as of October 31, '20 and that compared favorably to the 47 days as of October 31, '19.
No one customer accounted for more than 10% of sales, and our top five customers represented approximately 24% and 20% of consolidated net sales in fiscal '20 and '19, respectively.
Our inventory turnover rate increased to 153 days for the year ended October 31, '20, as compared to 124 days for the year ended October 31, '19.
Given this uncertainty, HEICO cannot provide fiscal '21 net sales and earnings guidance at this time.
However, we do believe our ongoing fiscal conservative policies, healthy balance sheet, increased liquidity will permit us to invest in new research and development and gain market share as the industry recovers.

Summary:
Consolidated net income per diluted share decreased 27% to $0.45 in the fourth quarter of fiscal '20, as compared to $0.62 in the fourth quarter of fiscal '19.
Given this uncertainty, HEICO cannot provide fiscal '21 net sales and earnings guidance at this time.
However, we do believe our ongoing fiscal conservative policies, healthy balance sheet, increased liquidity will permit us to invest in new research and development and gain market share as the industry recovers.