Table: transit_specs
Columns: year
manufacturer
model
length_ft
fuel_or_propulsion
fleet_series
quantity

Question: Tell me the model with fuel or propulsion of diesel and orion manufacturer in 2005
SQL: SELECT "model" FROM transit_specs WHERE "fuel_or_propulsion" = 'diesel' AND "manufacturer" = 'orion' AND "year" = 2005

Question: Name the sum of quantity for before 2011 model slf-230
SQL: SELECT SUM("quantity") FROM transit_specs WHERE "year" < 2011 AND "model" = 'slf-230'

Question: Name the fleet series with a quantity of 5
SQL: SELECT "fleet_series" FROM transit_specs WHERE "quantity" = 5