Years Ended December 31,
Years Ended December 31,
Years Ended December 31,
2019
2018
2017
Federal income tax expense at statutory rates
$11,061
$8,690
$10,892
Effect of:
State income taxes, net of federal benefit
2,973
2,665
2,244
Impact of foreign operations
11
146
74
Non-deductible expenses
592
1,274
1,350
Federal tax rate change
—
—
9,046
Tax effect of TCJA from foreign earnings
28
130
2,296
Other
581
645
239
Changes in valuation allowance
92
835
273
Income tax expense
$15,154
$12,715
$25,242
5 .
income taxes : -continued .
in the normal course of business the company takes positions on its tax returns that may be challenged by taxing authorities .
the company evaluates all uncertain tax positions to assess whether the position will more likely than not be sustained upon examination .
if the company determines that the tax position is not more likely than not to be sustained the company records a liability for the amount of the benefit that is not more likely than not to be realized when the tax position is settled .
the company does not have a liability for uncertain tax positions at december 31 2019 and does not expect that its liability for uncertain tax positions will materially increase during the twelve months ended december 31 2020 however actual changes in the liability for uncertain tax positions could be different than currently expected .
if recognized changes in the company ' s total unrecognized tax benefits would impact the company ' s effective income tax rate .
in the normal course of business the company takes positions on its tax returns that may be challenged by taxing authorities .
the company evaluates all uncertain tax positions to assess whether the position will more likely than not be sustained upon examination .
if the company determines that the tax position is not more likely than not to be sustained the company records a liability for the amount of the benefit that is not more likely than not to be realized when the tax position is settled .
the company does not have a liability for uncertain tax positions at december 31 2019 and does not expect that its liability for uncertain tax positions will materially increase during the twelve months ended december 31 2020 however actual changes in the liability for uncertain tax positions could be different than currently expected .
if recognized changes in the company ' s total unrecognized tax benefits would impact the company ' s effective income tax rate .
in the normal course of business the company takes positions on its tax returns that may be challenged by taxing authorities .
the company evaluates all uncertain tax positions to assess whether the position will more likely than not be sustained upon examination .
if the company determines that the tax position is not more likely than not to be sustained the company records a liability for the amount of the benefit that is not more likely than not to be realized when the tax position is settled .
the company does not have a liability for uncertain tax positions at december 31 2019 and does not expect that its liability for uncertain tax positions will materially increase during the twelve months ended december 31 2020 however actual changes in the liability for uncertain tax positions could be different than currently expected .
if recognized changes in the company ' s total unrecognized tax benefits would impact the company ' s effective income tax rate .
in the normal course of business the company takes positions on its tax returns that may be challenged by taxing authorities .
the company evaluates all uncertain tax positions to assess whether the position will more likely than not be sustained upon examination .
if the company determines that the tax position is not more likely than not to be sustained the company records a liability for the amount of the benefit that is not more likely than not to be realized when the tax position is settled .
the company does not have a liability for uncertain tax positions at december 31 2019 and does not expect that its liability for uncertain tax positions will materially increase during the twelve months ended december 31 2020 however actual changes in the liability for uncertain tax positions could be different than currently expected .
if recognized changes in the company ' s total unrecognized tax benefits would impact the company ' s effective income tax rate .
the company or one of its subsidiaries files income tax returns in the us federal jurisdiction and various state and foreign jurisdictions .
the company is subject to us federal tax and state tax examinations for years 2004 to 2019 .
the company is subject to tax examinations in its foreign jurisdictions generally for years 2005 to 2019 .
the following is a reconciliation of the federal statutory income taxes to the amounts reported in the financial statements -in thousands .

Question: What are the respective federal income tax expense at statutory rates in 2017 and 2018?
Answer: 10,892 8,690