CREATE TABLE table_54791 ("Player" TEXT, "Total Win-Loss" TEXT, "Singles Win-Loss" TEXT, "Doubles Win-Loss" TEXT, "No. of ties" FLOAT, "First year played" FLOAT, "Years Played" FLOAT)

How many years did the team that has a Singles win-Loss of 4-9 and first played before 1999?
SELECT SUM("Years Played") FROM table_54791 WHERE "Singles Win-Loss" = '4-9' AND "First year played" < '1999'
SELECT SUM("Years Played") FROM "table_54791" WHERE "First year played" < '1999' AND "Singles Win-Loss" = '4-9'