You have bought on margin 100 zero-coupon bonds, with face value \(€ 1000\), maturing in three years. At present, the annual yield (annual return with annual compounding) of the bonds is \(4.3 \%\). The initial margin ratio is \(50 \%\), and the maintenance margin is \(20 \%\). Assuming that we neglect the passage of time, for which yield will you get a margin call?