Consider this : https://en.wikipedia.org/wiki/Earth_mass#Variation
The main factor in mass gain is in-falling material, cosmic dust, meteors, etc. are the most significant contributors to Earth's increase in mass. The sum of material is estimated to be 37000 to 78000 tons annually
I would like to know, if there is an estimate of chemical composition of mass. That is , I am looking for a categorization of this mass in x% Carbon, y% Silicon, etc.