Comparing rates of return for different assets using $V=Pe^{rT}$

I have been playing with $V=Pe^{rT}$ and have been thinking about how to apply it to situations involving different assets growing at different rates.

Suppose I had data for the historic sale prices of a row of houses in a street, with two data points per house. My assumption here is going to be that each house’s price grows according to $V=Pe^{rT}$, with $r$ constant.

Using $V=Pe^{rT}$, I could calculate each house’s instantaneous rate of interest $r=frac{ln{V}-ln{P}}{T}$, and its APR $hat{r}=e^{r}-1$, where $T=B-A$ is the number of years elapsed.

My question is, how should I meaningfully combine the growth rates of the different houses? Say I want a figure for the street’s overall growth rate in order to evaluate whether a particular house has been growing more quickly or more slowly than this rate. I have various ideas:

• Take the average of the $r_{i}$, which is 5.138%
• Use $-1+e^{5.138%}=5.272%$
• Take the average of the $hat{r}_{i}$, which is 5.346%
• Work out the houses’ prices in two base years (say, 2000 and 2021), using $P=Ve^{-rT}$, and work out what my $r$ or $hat{r}$ would have been if I’d bought the entire street in 2000 and kept the houses until 2021.

Using the totals above as my new $P$ and $V$, I get that $r=6.91%$ and $hat{r}=7.15%$.

Is this a legitimate method? If so, what is it called? I am concerned that it might not be legitimate, because changing the two base years gives different results:

Here, $r=6.19%$ and $hat{r}=6.39%$, which seems strange, since each individual house’s growth rate was constant. Does this mean that the "What if I’d bought the whole street in year $X$ and waited until year $Y$" method is wrong, or does it still have an interpretation?

What is the best way of defining the "overall" rate of growth for the whole street of houses?

Thanks