Complex sentence: At the start of the program in 1987 the European Union had only 12 member states, around 3,000 students received grants to study for a period of 6 to 12 months at a host university of another European member state.
Split into simpler sentences: At the start of the program in 1987, the European Union had only 12 member states. Around 3,000 students received grants to study for a period of 6 to 12 months at a host university of another European member state.