Overshoot more than 100%
Do you mean peak overshoot or percentage overshoot? They are not the same.

Peak overshoot (expressed in percent) is: \$\frac{peak\:value}{final\:value}\small \: .\:100\$%

Percentage overshoot is: \$\frac{peak\:value\:-\:final\:value}{final\:value}\:.\:\small 100\$%

e.g. for a unit step input, a final value of unity, and a peak value of 1.6, the percentage overshoot is 60% and the peak overshoot is 160%.