Non-GAAP (Core) Financial Measures
The following discussion and analysis of our financial condition and results of operations include certain non-GAAP financial measures as identified in the reconciliation below. The non-GAAP financial measures disclosed herein do not have standard meaning and may vary from the non-GAAP financial measures used by other companies or how we may calculate those measures in other instances from time to time. Non-GAAP financial measures should not be considered a substitute for, or superior to, measures of financial performance prepared in accordance with U.S. GAAP. Also, our “core” financial measures should not be construed as an inference by us that our future results will be unaffected by those items that are excluded from our “core” financial measures.
Management believes that the non-GAAP “core” financial measures set forth below are useful to facilitate evaluating the past and future performance of our ongoing manufacturing operations over multiple periods on a comparable basis by excluding the effects of the amortization of intangibles, stock-based compensation expense and related charges, restructuring and related charges, distressed customer charges, acquisition and integration charges, loss on disposal of subsidiaries, settlement of receivables and related charges, impairment of notes receivable and related charges, goodwill impairment charges, business interruption and impairment charges, net, other than temporary impairment on securities, restructuring of securities loss, income (loss) from discontinued operations, gain (loss) on sale of discontinued operations and certain other expenses, net of tax and certain deferred tax valuation allowance charges. Among other uses, management uses non-GAAP “core” financial measures to make operating decisions, assess business performance and as a factor in determining certain employee performance when evaluating incentive compensation. Management believes that the non-GAAP “core” financial measures set forth below are useful to facilitate evaluating the past and future performance of our ongoing manufacturing operations over multiple periods on a comparable basis by excluding the effects of the amortization of intangibles, stock-based compensation expense and related charges, restructuring and related charges, distressed customer charges, acquisition and integration charges, loss on disposal of subsidiaries, settlement of receivables and related charges, impairment of notes receivable and related charges, goodwill impairment charges, business interruption and impairment charges, net, other than temporary impairment on securities, restructuring of securities loss, income (loss) from discontinued operations, gain (loss) on sale of discontinued operations and certain other expenses, net of tax and certain deferred tax valuation allowance charges. Among other uses, management uses non-GAAP “core” financial measures to make operating decisions, assess business performance and as a factor in determining certain employee performance when evaluating incentive compensation. Management believes that the non-GAAP “core” financial measures set forth below are useful to facilitate evaluating the past and future performance of our ongoing manufacturing operations over multiple periods on a comparable basis by excluding the effects of the amortization of intangibles, stock-based compensation expense and related charges, restructuring and related charges, distressed customer charges, acquisition and integration charges, loss on disposal of subsidiaries, settlement of receivables and related charges, impairment of notes receivable and related charges, goodwill impairment charges, business interruption and impairment charges, net, other than temporary impairment on securities, restructuring of securities loss, income (loss) from discontinued operations, gain (loss) on sale of discontinued operations and certain other expenses, net of tax and certain deferred tax valuation allowance charges. Among other uses, management uses non-GAAP “core” financial measures to make operating decisions, assess business performance and as a factor in determining certain employee performance when evaluating incentive compensation.
We determine the tax effect of the items excluded from “core” earnings and “core” diluted earnings per share based upon evaluation of the statutory tax treatment and the applicable tax rate of the jurisdiction in which the pre-tax items were incurred, and for which realization of the resulting tax benefit, if any, is expected. In certain jurisdictions where we do not expect to realize a tax benefit (due to existing tax incentives or a history of operating losses or other factors resulting in a valuation allowance related to deferred tax assets), a reduced or 0% tax rate is applied.
We are reporting “core” operating income, “core” earnings and “core” return on invested capital to provide investors with an additional method for assessing operating income and earnings, by presenting what we believe are our “core” manufacturing operations. A significant portion (based on the respective values) of the items that are excluded for purposes of calculating “core” operating income and “core” earnings also impacted certain balance sheet assets, resulting in a portion of an asset being written off without a corresponding recovery of cash we may have previously spent with respect to the asset. In the case of restructuring and related charges, we may make associated cash payments in the future. In addition, although, for purposes of calculating “core” operating income and “core” earnings, we exclude stock-based compensation expense (which we anticipate continuing to incur in the future) because it is a non-cash expense, the associated stock issued may result in an increase in our outstanding shares of stock, which may result in the dilution of our stockholders’ ownership interest. We encourage you to consider these matters when evaluating the utility of these non-GAAP financial measures.
Included in the tables below are a reconciliation of the non-GAAP financial measures to the most directly comparable U.S. GAAP financial measures as provided in our Consolidated Financial Statements:
Reconciliation of U.S. GAAP Financial Results to Non-GAAP Measures
(1) Charges during fiscal years 2019 and 2018 relate to inventory and other assets charges for certain distressed customers in the networking and consumer wearables sectors. Charges during fiscal year 2017 relate to inventory and other assets charges for the disengagement with an energy customer.
(2) Charges, net of insurance proceeds of $2.9 million and $24.9 million, for the fiscal years ended August 31, 2019 and 2018, respectively, relate to business interruption and asset impairment costs associated with damage from Hurricane Maria, which impacted our operations in Cayey, Puerto Rico.
(3) Charges related to our strategic collaboration with Johnson & Johnson Medical Devices Companies (“JJMD”).
(4) Relates to a restructuring of securities loss on available for sale securities during fiscal year 2019. See Note 16 – “Fair Value Measurements” to the Consolidated Financial Statements for further discussion.
(5) The fiscal year ended August 31, 2019 includes a $13.3 million income tax benefit for the effects of the Tax Act recorded during the three months ended November 30, 2018. The fiscal year ended August 31, 2018 includes a $142.3 million provisional estimate to account for the effects of the Tax Act.
Table:
 |  | Fiscal Year Ended August 31, | 
(in thousands, except for per share data) | 2019 | 2018 | 2017
Operating income (U.S. GAAP) | $701,356 | $542,153 | $410,230
Amortization of intangibles | 31,923 | 38,490 | 35,524
Stock-based compensation expense and related charges | 61,346 | 98,511 | 48,544
Restructuring and related charges | 25,914 | 36,902 | 160,395
Distressed customer charges(1) | 6,235 | 32,710 | 10,198
Business interruption and impairment charges, net(2) | (2,860) | 11,299 | —
Acquisition and integration charges(3) | 52,697 | 8,082 | —
Loss on disposal of subsidiaries | — | — | 2,112
Adjustments to operating income | 175,255 | 225,994 | 256,773
Core operating income(Non-GAAP) | $876,611 | $768,147 | $667,003
Net income attributable to Jabil Inc.(U.S.GAAP) | $287,111 | $86,330 | $129,090
Adjustments to operating income | 175,255 | 225,994 | 256,773
Other than temporary impairment on securities | — | — | 11,539
Restructuring of securities loss(4) | 29,632 | — | —
Adjustment for taxes(5) | (18,633) | 146,206 | (4,726)
Core earnings(Non-GAAP) | $473,365 | $458,530 | $392,676
Diluted earnings per share(U.S.GAAP) | $1.81 | $0.49 | $0.69
Diluted core earnings per share(Non-GAAP) | $2.98 | $2.62 | $2.11
Diluted weighted average shares outstanding used in the calculation of earnings per share (U.S. GAAP and Non-GAAP) | 158,647 | 175,044 | 185,838


Question: How many years did Operating income (U.S. GAAP) exceed $500,000 thousand?
Answer: 2
Calculation: 2019##2018