CREATE TABLE table_51255 ("Mountain West" TEXT, "Lost" FLOAT, "Tied" FLOAT, "Pct." FLOAT, "Years" FLOAT, "Total Games" FLOAT)

How many years for the team with under 31 ties and a percentage of 0.5451?
SELECT "Years" FROM table_51255 WHERE "Tied" < '31' AND "Pct." = '0.5451'
SELECT "Years" FROM "table_51255" WHERE "Pct." = '0.5451' AND "Tied" < '31'