The next enlargement was in 1981 when Greece joined Europe, Spain and Portugal both following in 1986. When we started the Maastricht negotiations, we knew already that there would be three additional candidates which joined Europe in 1995: Finland, Austria and Sweden.
Even though the Maastricht Treaty was ratified in 1992, you ought to know that during the discussions and negotiations, we already tried to take into account the enlarged Europe when we designed the built-up of the institutions that were to run the single currency.