From the graph,
The number of persons in the age group $$10-15$$ is $$=1400$$.
The number of persons in the age group $$20-25$$ is $$=1200$$.
The number of persons in the age group $$30-35$$ is $$=1100$$.
The number of persons in the age group $$40-45$$ is $$=1000$$.
The number of persons in the age group $$50-55$$ is $$=900$$.
The number of persons in the age group $$60-65$$ is $$=800$$.
The number of persons in the age group $$70-75$$ is $$=300$$.