human
Considering the provided database schema and associated query, produce SQL code to retrieve the answer to the query. 
###Database Schema: Model, Chassis, Engine, Year From, Year To
###Question: How many engines have a Model of sl600, and a Year From of 1994, and a Year To smaller than 1995?
gpt
SELECT COUNT Engine FROM table WHERE Model = sl600 AND Year From = 1994 AND Year To < 1995