Hilltop Rubber produces specialized bike tires for Orange Bikes in Ohio. Hilltop Rubber is worried about the exact width$($s$)$ of their tires for this customer. Based on their intended product design, the company has a lower specification limit $($LSL$)$ of $22\mathrm{.}9mm$ and an upper specification limit $($USL$)$ of $23\mathrm{.}6mm.$ The standard deviation is $0\mathrm{.}19mm$ and the mean is $23\mathrm{.}2mm.$

$($Round your answer to $4$ decimal places.$)$

What is the process capability index for the process?