CREATE TABLE table_1636 ("Period" TEXT, "% trains arriving within 5 mins of scheduled time  ( over three months ) " TEXT, "Change over same quarter the previous year" TEXT, "% trains arriving within 5 mins of scheduled time Moving Annual Average  ( MAA ) " TEXT, "Change over previous year as a whole" TEXT)

What's the change over same quarter the previous year in the period when the 89.6% of the trains arrive within 5 minutes of scheduled time (over three months)?
SELECT "Change over same quarter the previous year" FROM table_1636 WHERE "% trains arriving within 5 mins of scheduled time (over three months)" = '89.6%'
SELECT "Change over same quarter the previous year" FROM "table_1636" WHERE "% trains arriving within 5 mins of scheduled time (over three months)" = '89.6%'