Question: When did the country, whose co-official language was used by the director of Group Portrait with a Lady, first attend the Olympics as an independent team?

Passages:
Group Portrait with a Lady () is a 1977 German-French drama film directed by Aleksandar Petrović. It was entered into the 1977 Cannes Film Festival. It is based on the novel of the same name. Aleksandar "Saša" Petrović (14 January 1929 – 20 August 1994) was a French-born acclaimed Serbian and Yugoslav film director who was one of the leading European directors in the 1960s and one of the major figures of the Yugoslav Black Wave. Two of his films were nominated for the Academy Award for Best Foreign Language Film: "Three" in 1966 and "I Even Met Happy Gypsies" ("Feather Gatherers") in 1967. The latter (original title "Skupljaci perja") was the first movie that presented the existence of Gypsies in society and everyday life; it was also the first full-feature film where Gypsies spoke their own language, Roma. Most roles were interpreted by real Gypsies; this was their movie. "As a child, I observed them and saw in these people faith and irrationality," said Petrović "I Even Met Happy Gypsies" won the FIPRESCI Prize and the Grand Prize of the Jury at the Cannes Film Festival; it also received a nomination for a Golden Globe. In 1967 Petrović was a member of the jury at the 17th Berlin International Film Festival. Serbian (српски / srpski, pronounced [sr̩̂pskiː]) is the standardized variety of the Serbo-Croatian language mainly used by Serbs. It is the official language of Serbia, co-official in the territory of Kosovo, and one of the three official languages of Bosnia and Herzegovina. In addition, it is a recognized minority language in Montenegro, where it is spoken by the relative majority of the population, as well as in Croatia, North Macedonia, Romania, Hungary, Slovakia, and the Czech Republic. Federal Republic of Yugoslavia, formed as a joint state by only Montenegro and Serbia after the breakup of Yugoslavia, from 1992–2002 (due to UN ban allowed to compete as Independent Olympic Participants at the 1992 Summer Olympics and was not allowed to compete at 1994 Winter Olympics)Two of the successor nations (Croatia and Slovenia) began to compete as independent teams at the Olympics starting at the 1992 Winter Games and Bosnia and Herzegovina at the 1992 Summer Games and as of the 2008 Summer Olympics, all six successor nations, former socialist republics, have participated independently. Kosovo, a former autonomous province, made its Olympic debut as an independent national team at the 2016 Summer Olympics.

Supporting sentences:
Group Portrait with a Lady () is a 1977 German-French drama film directed by Aleksandar Petrović. Aleksandar "Saša" Petrović (14 January 1929 – 20 August 1994) was a French-born acclaimed Serbian and Yugoslav film director who was one of the leading European directors in the 1960s and one of the major figures of the Yugoslav Black Wave. It is the official language of Serbia, co-official in the territory of Kosovo, and one of the three official languages of Bosnia and Herzegovina. Kosovo, a former autonomous province, made its Olympic debut as an independent national team at the 2016 Summer Olympics.