Year ended
July 31,

Description

Balance at
Beginning
of period

Charged
to
costs
and expenses

Charged
to other
accounts

Deductions

Balance at
end of period

2012

Allowance for doubtful accounts receivable

3,488

5,104

5,319

(1)

3,273

2011

Allowance for doubtful accounts receivable

2,839

4,431

3,782

(1)

3,488

2010

Allowance for doubtful accounts receivable

4,786

3,480

5,427

(1)

2,839

2012

Deferred tax valuation allowance

32,920

8,341

41,261

2011

Deferred tax valuation allowance

28,901

4,019

32,920

2010

Deferred tax valuation allowance

21,716

7,185

28,901