While world airlines have faced many difficulties, Singapore Airlines (SIA) has weathered the storms better than others. Many airlines, since 1990 have suffered extensive losses. American airlines have lost about US$6.5 billion. Pan Am folded and several carriers filed for bankruptcy protection. While Asian airlines have been more successful (i.e. Cathay Pacific and China Airlines), SIA had been the more successful than the competition in many cases. While Cathay Pacific and China Airlines earned US$813 million in 1991 with seventy-three planes, Singapore Airlines earned US$912.8 million with fifty planes.