Prior Depreciation entry in rental property asset field

I'm entering depreciation asset data for an owner-use rental property.  Past year to year owner use was variable, i.e.; business-use was between 85% to 100% in any given year.   In less-than-100% business-use years, less than standard depreciation allowances were used to compute my taxes.

In calculating current year depreciation amounts allowed, it is not clear to me what is requested by any particular asset's entry field asking for Prior Depreciation. 

Does that mean

1.  the prior years' depreciation expenses as IF, in prior years, I always claimed 100% business use (i.e.; no personal use) - that is, the 'standard' depreciation schedule accumulated value?             Or does it mean
2.  the prior years' actual depreciation expenses accumulated - derated due to some prior years having less than 100% business-use?

If I use path 2. above, then my current year's depreciation amount for that asset is higher than the 'standard' depreciation schedule value - as if trying to make up for my shorting prior unused but available depreciation.  Is path 2. the valid interpretation?