Core’s dual listing on the NYSE Euronext  Exchange in Amsterdam also had a  successful year, as European ownership  climbed from 12% to 20%, a 67%  increase and the highest European  ownership level of any major oilfield  service company. Core continues to follow the three  financial tenets that have led to our  industry-leading total shareholder  returns (TSR) over fifteen-, ten-, five-,  three-, and one-year investment time  horizons (Table 2).  On 10 July 2013, Core celebrated the  fifteenth anniversary of its NYSE listing,  and Core’s Executive and Operating  Management Team had the honor of  ringing the opening bell that morning  (Figure 2).  Table 2: Annualized Total Shareholder Return, % Figure 2. Executive and Operating Management Team ringing the opening  bell on the fifteenth anniversary of Core’s NYSE listing. Company Name One Year Three Years Five Years Ten Years Fifteen  Years Since CLB IPO Core Laboratories  76.3 30.2 46.4 37.6 22.6 25.9 Schlumberger  32.1 4.1 18.0 14.0 11.7 11.7 Halliburton  48.0 8.6 24.2 15.9 10.1 10.8 National Oilwell Varco  17.8 6.6 28.1 22.4 19.8 — Baker Hughes  37.0 0.0 12.9 6.7 9.2 6.5 Transocean 14.4 –7.9 2.8 7.8 4.5 6.4 Weatherford International  38.4 –12.1 7.4 5.6 11.0 12.0 Nabors Industries  18.8 –9.9 7.5 –1.9 6.4 7.2 Superior Energy Services  28.4 –8.7 10.8 11.0 16.1 13.5 Carbo Ceramics  50.8 5.2 28.3 14.3 17.9 — Key Energy Services 13.7 –15.2 12.4 –2.6 3.5 2.4 CGG  –41.8 –15.8 4.2 10.1 4.4 5.0 Source: Bloomberg December 2013