In the table below, we provide you with our selected financial and operating data. We have prepared the statement of income and balance sheet data using our consolidated financial statements for the five years ended December 31, 2000. When you read this selected financial and operating data, it is important that you read along with it the historical financial statements and related notes included elsewhere in this Report, as well as the section of this Report captioned “Management’s Discussion and Analysis of Financial Condition and Results of Operations.”
Year Ended December 31,
(in thousands, except per share data)       1996     1997     1998     1999     2000  
Statement of income data:
Net revenue $ 71,273 $ 117,326 $ 171,298 $ 226,290 $ 268,836
Direct expenses:
  Employee costs 19,895 33,429 46,878 61,224 78,051
  Orthodontic supplies 5,428 8,789 13,287 17,136 21,274
  Rent 6,114 10,299 14,128 18,624 23,973
  Marketing and advertising 6,644 9,855 15,491 16,874 22,001
Total direct expenses 38,081 62,372 89,784 113,858 145,299
General and administrative 8,703 13,356 18,104 23,270 28,360
Depreciation and amortization 2,814 5,640 9,124 12,238 15,175
Operating profit 21,675 35,958 54,286 76,924 80,002
Interest (expense) income, net 1,935 1,143 280 (2,204 ) (3,731 )
Income before income taxes 23,610 37,101 54,566 74,720 76,271
Provision for income taxes 9,208 14,469 20,753 28,206 28,549
Income before cumulative effect
 of changes in accounting principles 14,402 22,632 33,813 46,514 47,772
Cumulative effect of changes in accounting
 principles, net of income tax benefit(1)(2) (678 ) (50,576 )
Net income (loss) $ 14,402 $  22,632 $  33,813 $  45,836 $  (2,854 )
Net income per share before cumulative effect
 of changes in accounting principles(3) $  .33 $  .50 $  .70 $  .96 $  .96
Cumulative effect of changes in accounting
 principles, net of income tax benefit, per share(1)(2) (.02 ) (1.02 )
Net income (loss) per share(3) $  .33 $  .50 $  .70 $  .94 $  (.06 )
Weighted average shares outstanding(3) 43,708 45,414 48,502 48,643 49,845
Pro forma net income for change in accounting
 principle adopted effective January 1, 2000(2)(4) $  8,288 $  12,013 $  22,276 $  32,326 N/A
Pro forma net income per share for change in
 accounting principle adopted effective January 1, 2000(2)(4) $  .19 $  .26 $  .46 $  .66 N/A
     
Year Ended December 31,
(in thousands, except percentage and per share data) 1996 1997 1998 1999 2000  
Operating data:
Number of orthodontic centers(5) 247 360 469 537 592
Comparable orthodontic center net revenue growth(6) 22.2 % 20.0 % 19.2 % 20.1 % 22.6 %(7)
Total case starts 44,910 70,611 95,377 126,307 160,639
     
As of December 31,
(in thousands) 1996 1997 1998 1999 2000  
Balance sheet data:
Cash and cash equivalents $  11,827 $  9,865 $  1,601 $  5,822 $  4,690
Working capital 40,219 68,243 59,634 102,276 39,573
Total assets(8) 142,460 224,805 292,472 362,816 367,947
Total debt 3,397 10,393 31,332 58,793 61,001
Total equity 114,887 190,740 231,159 278,527 287,196
 
(1)   See Note 2 to our Consolidated Financial Statements included elsewhere in this Report for information regarding the cumulative effect of a change in accounting principle effective January 1, 1999 related to Statement of Position 98-5, “Reporting on the Costs of Start-Up Activities.”
(2) See Note 2 to our Consolidated Financial Statements included elsewhere in this Report for information regarding the cumulative effect of a change in accounting principle effective January 1, 2000 related to revenue recognition and Staff Accounting Bulletin No. 101, “Revenue Recognition in Financial Statements” (“SAB 101”).
(3) These amounts represent the full dilutive effect of the exercise of common equivalent shares (stock options) outstanding during the year. See Note 6 to our Consolidated Financial Statements included elsewhere in this Report.
(4) Pro forma amounts were calculated assuming our change in revenue recognition effective January 1, 2000 pursuant to SAB 101 had been in effect for all periods presented.
(5) These amounts are presented as of the end of the period.
(6) These amounts represent the growth in net revenue in the indicated period relative to the comparable prior-year period by orthodontic centers that were affiliated with us throughout each of the two periods being compared. There were 53 of these comparable orthodontic centers in 1995, 75 in 1996, 130 in 1997, 227 in 1998, 332 in 1999, and 469 in 2000. The amount of that growth has been significantly affected by the number of newly-opened orthodontic centers included in the computation, because newly-opened orthodontic centers have experienced significant growth during their first 26 months of operations. The average term of a patient contract is about 26 months. Our affiliated orthodontic centers have typically reached maturity as patients are added during the first 26 months of operations.
(7) This amount represents the growth in net revenue in 2000 for orthodontic centers open throughout 1999 and 2000, compared to pro forma net revenue for these centers in 1999, calculated as if our change in accounting principle pursuant to SAB 101 effective January 1, 2000 had been in effect throughout 1999 and 2000. See “Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations—Revenue Recognition.”
(8) To conform to the balance sheet presentation as of December 31, 2000, amounts reported as of December 31, 1996, 1997, 1998 and 1999 as patient prepayments (previously reported as a liability) have been reclassified as a reduction of service fees receivable.