dutycycle=100 x compare value/period.
this is not quite correct
dutycycle=100 x compare value/period value
So the period value should be set to 19 (giving a period of 20 pulses) the input clock to 10kHz and the compare value to 10.
Always leave some room for adjustings, you could have choosen as well
Period value = 199, input clock 100kHz, compare value = 100.
This settings would allow for a 1% resolution setting of the duty cycle.