 Complete the following phrase:  Deadline for completion was 1 May 1979, but the rapidly deteriorating economic situation in Yugoslavia at the time slowed construction and the project was halted in 1980. In May 1984, the notion of abandoning the project altogether, due to high costs, was officially considered for the first time. Construction resumed in 1990 and in the next several years was stopped and restarted several times. The project itself was simplified. In 1996 a new contract was signed with the Energoprojekt company. The President of Serbia Slobodan Milošević and Prime Minister Mirko Marjanović officially opened the construction of the concrete roof slab on 7 July 1996, which was for the most part finished in 1999, but the building was halted again due to the 