| Total sales and operating income classified by major geographic area in which the company operates | 
Total sales to external customers, inter-segment sales, depreciation expense, amortization expense, income from operations, property, plant and equipment, net and total assets for each of our four reportable segments are as follows: 
 
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   | 
Three Months Ended September 30, 2018  | 
   | 
Three Months Ended September 30, 2017  | 
   | 
Six Months Ended September 30, 2018  | 
   | 
Six Months Ended September 30, 2017  | 
 
Sales to External Customers:  | 
   | 
 
  | 
   | 
   | 
 
  | 
   | 
   | 
   | 
   | 
 
United States and Latin America  | 
$  | 
32,653  | 
 
  | 
   | 
$  | 
21,318  | 
 
  | 
   | 
$  | 
64,282  | 
 
  | 
   | 
$  | 
44,869  | 
 
  | 
 
Canada  | 
30,967  | 
 
  | 
   | 
15,437  | 
 
  | 
   | 
59,595  | 
 
  | 
   | 
27,536  | 
 
  | 
 
Europe, Middle East and Africa  | 
15,564  | 
 
  | 
   | 
17,447  | 
 
  | 
   | 
36,367  | 
 
  | 
   | 
28,064  | 
 
  | 
 
Asia-Pacific  | 
10,970  | 
 
  | 
   | 
7,429  | 
 
  | 
   | 
18,812  | 
 
  | 
   | 
12,898  | 
 
  | 
 
   | 
$  | 
90,154  | 
 
  | 
   | 
$  | 
61,631  | 
 
  | 
   | 
$  | 
179,056  | 
 
  | 
   | 
$  | 
113,367  | 
 
  | 
 
Inter-Segment Sales:  | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
United States and Latin America  | 
$  | 
13,878  | 
 
  | 
   | 
$  | 
14,309  | 
 
  | 
   | 
$  | 
25,807  | 
 
  | 
   | 
$  | 
23,891  | 
 
  | 
 
Canada  | 
1,163  | 
 
  | 
   | 
1,895  | 
 
  | 
   | 
2,216  | 
 
  | 
   | 
3,359  | 
 
  | 
 
Europe, Middle East and Africa  | 
858  | 
 
  | 
   | 
362  | 
 
  | 
   | 
1,963  | 
 
  | 
   | 
723  | 
 
  | 
 
Asia-Pacific  | 
352  | 
 
  | 
   | 
174  | 
 
  | 
   | 
497  | 
 
  | 
   | 
547  | 
 
  | 
 
   | 
$  | 
16,251  | 
 
  | 
   | 
$  | 
16,740  | 
 
  | 
   | 
$  | 
30,483  | 
 
  | 
   | 
$  | 
28,520  | 
 
  | 
 
Depreciation Expense:  | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
United States and Latin America  | 
$  | 
1,190  | 
 
  | 
   | 
$  | 
1,078  | 
 
  | 
   | 
$  | 
2,310  | 
 
  | 
   | 
$  | 
2,064  | 
 
  | 
 
Canada  | 
934  | 
 
  | 
   | 
635  | 
 
  | 
   | 
1,945  | 
 
  | 
   | 
1,240  | 
 
  | 
 
Europe, Middle East and Africa  | 
108  | 
 
  | 
   | 
124  | 
 
  | 
   | 
217  | 
 
  | 
   | 
214  | 
 
  | 
 
Asia-Pacific  | 
42  | 
 
  | 
   | 
32  | 
 
  | 
   | 
82  | 
 
  | 
   | 
64  | 
 
  | 
 
   | 
$  | 
2,274  | 
 
  | 
   | 
$  | 
1,869  | 
 
  | 
   | 
$  | 
4,554  | 
 
  | 
   | 
$  | 
3,582  | 
 
  | 
 
Amortization Expense:  | 
   | 
   | 
   | 
   | 
   | 
   | 
   | 
 
United States and Latin America  | 
$  | 
1,460  | 
 
  | 
   | 
$  | 
1,505  | 
 
  | 
   | 
$  | 
2,965  | 
 
  | 
   | 
$  | 
3,010  | 
 
  | 
 
Canada  | 
3,424  | 
 
  | 
   | 
901  | 
 
  | 
   | 
7,073  | 
 
  | 
   | 
1,741  | 
 
  | 
 
Europe, Middle East and Africa  | 
346  | 
 
  | 
   | 
350  | 
 
  | 
   | 
703  | 
 
  | 
   | 
679  | 
 
  | 
 
Asia-Pacific  | 
266  | 
 
  | 
   | 
266  | 
 
  | 
   | 
532  | 
 
  | 
   | 
532  | 
 
  | 
 
   | 
$  | 
5,496  | 
 
  | 
   | 
$  | 
3,022  | 
 
  | 
   | 
$  | 
11,273  | 
 
  | 
   | 
$  | 
5,962  | 
 
  | 
 
Income (loss) from operations:  | 
   | 
 
  | 
   | 
   | 
 
  | 
   | 
   | 
   | 
   | 
 
United States and Latin America  | 
$  | 
2,849  | 
 
  | 
   | 
$  | 
(1,050  | 
)  | 
   | 
$  | 
5,585  | 
 
  | 
   | 
$  | 
(2,097  | 
)  | 
 
Canada  | 
4,410  | 
 
  | 
   | 
6,549  | 
 
  | 
   | 
7,695  | 
 
  | 
   | 
9,997  | 
 
  | 
 
Europe, Middle East and Africa  | 
1,055  | 
 
  | 
   | 
2,378  | 
 
  | 
   | 
3,703  | 
 
  | 
   | 
2,232  | 
 
  | 
 
Asia-Pacific  | 
1,773  | 
 
  | 
   | 
845  | 
 
  | 
   | 
2,669  | 
 
  | 
   | 
1,307  | 
 
  | 
 
Unallocated:  | 
 
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   | 
 
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   | 
 
  | 
 
  | 
   | 
 
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Stock compensation  | 
(1,085  | 
)  | 
   | 
(947  | 
)  | 
   | 
(2,089  | 
)  | 
   | 
(1,732  | 
)  | 
 
Public company costs  | 
(330  | 
)  | 
   | 
(358  | 
)  | 
   | 
(651  | 
)  | 
   | 
(732  | 
)  | 
 
   | 
$  | 
8,672  | 
 
  | 
   | 
$  | 
7,417  | 
 
  | 
   | 
$  | 
16,912  | 
 
  | 
   | 
$  | 
8,975  | 
 
  | 
 
  
 
 
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   | 
September 30, 2018  | 
   | 
March 31, 2018  | 
 
Property, plant and equipment, net:  | 
   | 
   | 
   | 
 
United States and Latin America  | 
$  | 
38,016  | 
 
  | 
   | 
$  | 
37,112  | 
 
  | 
 
Canada  | 
32,483  | 
 
  | 
   | 
33,076  | 
 
  | 
 
Europe, Middle East and Africa  | 
3,253  | 
 
  | 
   | 
3,567  | 
 
  | 
 
Asia-Pacific  | 
675  | 
 
  | 
   | 
730  | 
 
  | 
 
   | 
$  | 
74,427  | 
 
  | 
   | 
$  | 
74,485  | 
 
  | 
 
Total Assets:  | 
   | 
   | 
   | 
 
United States and Latin America  | 
$  | 
207,741  | 
 
  | 
   | 
$  | 
213,099  | 
 
  | 
 
Canada  | 
315,496  | 
 
  | 
   | 
317,635  | 
 
  | 
 
Europe, Middle East and Africa  | 
85,936  | 
 
  | 
   | 
89,379  | 
 
  | 
 
Asia-Pacific  | 
41,105  | 
 
  | 
   | 
42,364  | 
 
  | 
 
   | 
$  | 
650,278  | 
 
  | 
   | 
$  | 
662,477  | 
 
  | 
 
  
 
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