These forward-looking statements involve risk and uncertainty. We also provide cementing services through the pressure pumping segment. Oil prices averaged $42.45 per barrel in the fourth quarter of 2020. Our active rig count has declined since the fourth quarter of 2018. Our average active rig count for the fourth quarter of 2020 was 62 rigs. Term contracts help support our operating rig count. The pressure pumping market remains oversupplied. On March 27, 2020, we entered into Amendment No. In conjunction with our restructuring, we closed our Canadian drilling operations. Some of these have been in short supply from time to time. Equipment — We generally design, assemble, maintain and inspect our own equipment. Our coverage includes aggregate policy limits and exclusions. We also utilize numerous independent subcontractors from various trades. In addition, some of our customers may self-source certain materials. When caused by human activity, such seismic activity is called induced seismicity. The EPA has not yet finalized this rule. An increasing number of our customers consider sustainability factors in awarding work. If any such effects were to occur, they could have an adverse effect on our operations. The cost of compliance with these laws and regulations could be substantial. Technology Disputes Could Negatively Impact Our Operations or Increase Our Costs. We believe that our existing facilities are suitable and adequate to meet our needs. We are party to various legal proceedings arising in the normal course of our business. All purchases executed to date have been through open market transactions. Purchases may be made at any time without prior notice. Shares of stock purchased under the buyback program are held as treasury shares. There is no expiration date associated with the buyback program. Our pressure pumping business operates primarily in Texas and the Appalachian region. See Note 20 of Notes to Consolidated Financial Statements for additional information. Average margin per total job is defined as margin divided by total jobs. Direct operating costs are also most impacted by these same factors. 38 Restructuring expenses were recognized in 2020 and related to severance costs. Charges associated with that decision totaled $2.2 million in 2019. There were no restructuring charges in the comparable periods of 2019. The net proceeds before offering expenses were approximately $347 million. These shares were acquired at fair market value. The maturity date under the Term Loan Agreement is June 10, 2022. Our credit rating is currently investment grade at one of the two ratings agencies. We were in compliance with these covenants at December 31, 2020. On December 16, 2019, we fully prepaid the Series B Notes. We used a portion of the net proceeds from the offering to prepay our Series B Notes. The 2028 Notes will mature on February 1, 2028. We pay interest on the 2029 Notes on May 15 and November 15 of each year. The 2029 Notes bear interest at a rate of 5.15% per annum. As of December 31, 2020, no amounts had been drawn under the letters of credit. The agreements expire in years 2021 and 2022. 2) Interest to be paid on the 2029 Notes using 5.15% coupon rate. ( We recorded a $48.4 million charge related to this retirement. The remaining components of this equipment are retired. There was no similar charge in 2020 or 2018. The timeframe over which oil prices and activity levels may recover is highly uncertain. All of the