The following is sales information by product and geographic area for the years ended December 31, 2002, 2001 and 2000: Sales by Product (In thousands) (In thousands) Sales by Geographic Region 2002 2001 2000) Digital Business Transport (DBT)/Total Reach $^{®}$‚ $44,932 $86,794 $141,996 ) High-bit-rate Digital Subscriber Line (HDSL)/T1 177,653 192,850 233,073 ) Systems 123,140 107,437 87,880 ) Total $345,725 $387,081 $462,949) 2002 2001 2000) United States $325,429 $369,422 $448,810 ) All Other 20,296 17,659 14,139 ) Total $345,725 $387,081 $462,949) Sales of ADTRAN’s network access equipment to Incumbent Local Exchange Carriers (ILECs) and major  independent telecommunications companies amounted to approximately 57%, 59% and 56% of total sales during  the years ended December 31, 2002, 2001 and 2000, respectively. ADTRAN’s Enterprise Networks Division sells a significant portion of products to value-added resellers through a multi-tier distribution system. Sales of this type amounting to 25%, 26% and 26% of ADTRAN’s revenue for each of the years ended December 31, 2002, 2001  and 2000, respectively, were routed through four primary fulfillment distributors. As of December 31, 2002, long-lived assets totaled $106,173,835, which includes $106,043,657 held in the United States and $130,179 held outside the United States. As of December 31, 2001, long-lived assets totaled $120,133,445, which includes $119,960,338 held in the United States and $173,107 held outside the United States. ADTRAN has certain contingent liabilities resulting from litigation arising in the normal course of business. Although the outcome of any litigation can never be certain, it is ADTRAN’s opinion that the outcome of such contingencies will not materially affect its business, operations, financial condition or cash flows. ADTRAN leases office space and equipment under operating leases which expire at various dates through 2005. As of December 31, 2002, future minimum rental payments under non-cancellable operating leases with original maturities of greater than 12 months are approximately as follows: 2003 $772,222 ) 2004 282,083 ) 2005 77,896 ) Total $1,132,201) Rental expense was approximately $2,081,000, $2,230,000 and $1,794,000 in 2002, 2001 and 2000, respectively. Additionally, ADTRAN has committed to invest an aggregate of $8,000,000 in two private equity funds, of which $835,674 has been invested to date. The duration of each of these commitments is five years with $3,000,000 expiring  in 2005 and $5,000,000 expiring in 2007. 33 Financial Results 10 Commitments and Contingencies