Another Question re Permanent Residency

After reading most of the posted messages, I am now slightly confused.

Is it 7 years or 5 years of consecutive stay with a valid ARC? Is it also 270 days or 183 days?

What about in my case?

Year 1998 Arrived in Taiwan on September. I had an ARC based on a student visa.

Year 1999 Around August, my student visa was cancelled and replaced with a work visa. I still used the same ARC though.

Year 2000 I had to leave the country around mid-April. The bushiban I worked for had my old ARC cancelled. I was gone for 4 months and I came back around mid-August.

        I was then issued another visa and ARC by the same bushiban effective September.

Year 2001 Renewed my visa for another year.

Year 2002 Will be renewing my visa again this coming September.

Which of the abovementioned years can be counted as part of my 7 year or 5 year stay?

How many more years do I need to stay?

Also, on a hopeful note, who handles the change from a temporary ARC to a permanent one? Is it the bushiban or me? If me, where should I go? How does one apply for a permanent residency?

Hope you can help me on this one, Richard.