CREATE TABLE table_8146 ("Year" FLOAT, "Tournament" TEXT, "Surface" TEXT, "Round" TEXT, "Winner" TEXT, "Score" TEXT, "Length" TEXT, "Ivanovic" FLOAT, "Jankovic" FLOAT)

What year did Ivanovic win with Ivanovic greater than 4 and round of R16?
SELECT SUM("Year") FROM table_8146 WHERE "Winner" = 'ivanovic' AND "Ivanovic" > '4' AND "Round" = 'r16'
SELECT SUM("Year") FROM "table_8146" WHERE "Ivanovic" > '4' AND "Round" = 'r16' AND "Winner" = 'ivanovic'