Find Year-on-Year Growth Rate

This is a common interview question that you MUST nail!

The formula is (value - last_year_value) / last_year_value. You can calculate last_year_value as
📌 𝙻𝙰𝙶(𝚟𝚊𝚕𝚞𝚎, 𝟷) 𝚘𝚟𝚎𝚛 (𝚘𝚛𝚍𝚎𝚛 𝚋𝚢 𝚟𝚊𝚕𝚞𝚎)

𝙻𝙰𝙶(𝚟𝚊𝚕𝚞𝚎,𝟷) gets the value from the previous row. 𝙻𝙰𝙶(𝚟𝚊𝚕𝚞𝚎,𝟸) gets the value from the row before the previous row.

STEPS:
1️⃣ Use 𝙻𝙰𝙶 to get last year's revenue. Then, find difference between this year and last year's revenue.
2️⃣ 𝙲𝙰𝚂𝚃 all INT to FLOAT. Calculate the growth rate by dividing the difference by last year's revenue.

Caution! Casting integer to float is important for growth rates of integer columns. Otherwise, integer division will occur (instead of float division).

What's the difference? Integer division 1/2=0, while float division 1/2=0.5.

👇 Full example below.