Credit score changes

I am writing to you for some information about my credit score. I have tried very hard to get through the maze or firewall of phone messages at experian without any success. I have an account with them but because I have an online account, when I get my credit updates I don't get a report number and the maze is impossible. The question I have about my credit score is: Why does a credit score drop 6 pts in a month. The only thing I did last month was to apply to an apartment complex for their credit approval. I was approved but according to someone I spoke to on the phone, that one thing cost me 6 points on my credit report. Last year my credit score was 565. There was some old debt and some disputable information on the report, so I went to work to clean it up. Last month my score was 635. I just got a notice of a change in my score and when I checked, I noticed the 6 point drop in the score. I noticed a web page about you and decided to write and ask you if you could help me understand this situation. I hope you can help?
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looks like youve done well
you can take a 6 point hit for inquiries keep rated credit open and below 79% balance to high credit limit. when two years pass from date of last activity
you score will jump if you have good credit going now the average american has a score of 684
so your are almost there
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one other thingif you get an installment loanyour balance to high credit limit will be maxed out until you pay it down to below 79%