Jobless claims continue to see-saw week-to-week as the advance figure for seasonally adjusted initial claims for unemployment benefits in the week ending July 21 was 353,000, a decrease of 35,000 from the previous week’s revised figure of 388,000, the Labor Department announced Thursday. This is the biggest drop in more than two years, but analysts caution it may be due to seasonal factors, such as the auto industry’s traditional temporary summer shutdowns for retooling. This year, however, some automakers, experiencing stronger sales, are putting shutdowns on hold. The four-week moving average, a less volatile number that flattens out week-to-week fluctuations in the data, was 367,250, a decrease of 8,750 from the previous week and the lowest level since last March. The number of Americans filing for continuing unemployment claims during the week ending July 14 was 3,287,000, a decrease of 30,000 from the prior week. The four-week moving average was 3,309,000, a decrease of 3,759 from the preceding week. States reported 2,556,456 persons claiming emergency unemployment benefits for the week ending July 7, an increase of 32,093 from the prior week. There were 3,172,428 claimants in the comparable week last year. The largest increases in initial jobless claims for the week ending July 14 were in Alabama, California, Georgia, North Carolina, and Oregon. The largest decreases were in Kentucky, Michigan, New York, Ohio and Pennsylvania.