Set Analysis with Fractile

[johnnyjohn]

Hi,

I'm trying to write a formula that will average values that are between the 5th percentile and the 95th percentile. 

Trying to do this with set analysis, but it doesn't seem to be working. What's wrong with the expression below? 

Thanks

avg({<p_is_cl_prev_bps = {">fractile(total ALL p_is_cl_prev_bps,0.05)"}, p_is_cl_prev_bps = {"<fractile(total ALL p_is_cl_prev_bps,0.95)"}>} p_is_cl_prev_bps)