How much water is produced in jet exhaust? If a jet has typical combustion efficiency, what equivilent amount of liquid water will be created per gallon of jet or kerosene fuel. An acceptable answer can be a ratio in weight or volume to the original unburned fuel. For example an answer might be 1 part in 50 by volume or 1/4oz per pound is converted to water. 

An answer in "water vapor" volume should be avoided because gas volume changes dramatically with altitude (pressure) and temperature. 

If you are also able to show a comparison for gasoline, that would be even better.
According to Wikipedia Kerosene consists of molecules containing 10..16 C-atoms.
Assuming that the molecules are mainly Alkanes with formula $C_nH_{2n+2}$:

$C_{10}H_{22}$: 10 * 12g + 22g = 142g Alkane contains 22g H which burns to 22g + 11 * 16g = 198g $H_2O$ 
Ratio Water/Kerosene = 198/142 = ca. 1.39 

$C_{16}H_{34}$: 16 * 12g + 34g = 226g Alkane contains 34g H which burns to 34g + 17 * 16g = 306g $H_2O$ 
Ratio Water/Kerosene = 306/226 = ca. 1.35 

I.e. you get something between 1.35g and 1.39g Water per 1g Kerosene.

Comparison to Gasoline:
Main difference of Gasoline is that molecule chains are shorter (4-12 C-atoms).
I.e. H/C-ratio will be higher, i.e. Gasoline will yield more water per fuel than Kerosene.