yes as bob says there is a 1/16 chance for a normal leader, 1/12 with a heroic epic.
but if you have only 10 elites in a long war you are doing something wrong. build more barracks and when a unit is promoted to elite, don't let him die. protect him and only use him to attack wounded divisions.
here's a snippet from another post of mine i am way too lazy to link to ...
in my current (huge) game as a military civ i've spawned so may great leaders i've lost track. i'm in the modern ages now and have built the following wonders with a leader: sun tzu's, bach's cathedral, copernicus' observatory, newton's university, sistine chapel, theory of evolution, hoover dam, & seti program. i earned a leader the turn i built the theory, letting me rush build the hoover dam immediately afterwards. i didn't even have any factories made yet. i built the pyramids, leonardo's workshop and the great library from scratch. i have a leader waiting to rush the internet. and i'm pretty confident i will get the other wonders too, seeing as i have 125 tanks and 375 bradleys.
so the moral is: unless it's a hyper-critical wonder (read - great library), build that army, get a victory, and build that heroic epic. not only does the epic churn out great culture (4/turn) but then you statistically will create a leader about every 12 elite victories.
yay