cash flow to taxable income ratio

[Jeremiah Purdum]

Doing some year end math and I'm looking back across the last few years. On a SFH the second year the cash flow to taxable income on my sch E was .39. It jumped to .81 and .84 the next two years (if I did my quick calculation for this year correctly). What are other people seeing for this. I realize I'm leaving money on the table if I did something wrong and the .39 is more accurate.

Depreciation is the same for all three years. There was some variation in the real estate taxes paid and some minor increase in rent. 

Thanks!