Table schema:
CREATE TABLE table_name_52 (l_100km_extra_urban VARCHAR, mpg_us_combined VARCHAR, fuel_type VARCHAR, mpg_uk_combined VARCHAR, l_100km_combined VARCHAR)

Question: What's the total L/100km extra urban fueled by diesel, when the mpg-UK combines is more than 19.2, mpg-US is less than 50 and the L/100m combined is less than 5.7?
SQL: SELECT COUNT(l_100km_extra_urban) FROM table_name_52 WHERE mpg_uk_combined > 19.2 AND l_100km_combined < 5.7 AND fuel_type = "diesel" AND mpg_us_combined < 50