original: progress in developing the tar was hindered by political and economic obstacles throughout the 1960s , 1970s and early 1980s .
simplifications: political and economic obstacles hindered the tar 's developmental progress throughout the 1960 's , 1970 's and early 1980 's . progress in developing the tar was difficult because of politics and money problems throughout the 1960s , 1970s and early 1980s . political and economic problems slowed tar development in the 1960s , 1970s , and early 1980s . the developing progress of tar was made difficult by political and economic problems from 1960 's to early 1980 's . the ongoing building of the trans-asian-railroad was bogged down by political and economic problems throughout the 1960s , the 1970s and the early 1980s . progress of the tar took many years because of political and economic obstacles . from the 1960s to the early 80 's politics and economics hindered the developement of tar . progress in developing the tar was interfered with by political and money-based obstacles throughout the 1960s , 1970s and early 1980s