The population of the Jews in Gorlice is not well documented or reliable before the later half of the 19th century.  There are statistics on the Jewish population from 1880 to 1910 though.  Looking first at the Gorlice district in 1880 there was a total of 74,072 residents and out of those 6.4% (4,755) were Jews.  Just in the city of Gorlice itself, there were 2,257 jews out of the around 5,000 residents of the city which is close to 50%.  The population of Jews in Gorlice grew to 7.5% of the Gorlice district composed of Jews in 1910 and 51% of residents in the City of Gorlice were Jewish at that time (3,495 out of 6,600).
Answer this question: How many more Jews in the City Gorlice were there in 1910 than there were in 1880?
1238