How many regions had rainfall infiltration (km 3/year) of 9.3?
create table table_25983027_1 (rainfall_by_depth__mm_year_ varchar, infiltration__km_3__year_ varchar, PRIMARY KEY (rainfall_by_depth__mm_year_))
select count(rainfall_by_depth__mm_year_) from table_25983027_1 where infiltration__km_3__year_ = "9.3"