How many years after the "Charter for the Kingdom of the Netherlands" was passed did unrest break out in Curaçao?
return Charter for the  Kingdom of the   Netherlands was  passed ;return unrest break out in  Curaçao ;return year of #1 ;return year of #2 ;return difference of #3 and  #4
['select', 'select', 'project', 'project', 'arithmetic']